/* ============================================================
   BNUZ Share — 校园资料共享平台 Design System
   Pure CSS, zero dependencies
   ============================================================ */

/* ----- Google Fonts ----- */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;500;600;700;800&family=Noto+Sans+SC:wght@400;500;600;700&display=swap');

/* ============================================================
   1. CSS CUSTOM PROPERTIES (Design Tokens)
   ============================================================ */
:root {
  /* — Brand(青绿品牌色,对标「暨了么」米白纸感风)— */
  --color-primary:        #0e7a6e;
  --color-primary-light:  #1aaa97;
  --color-primary-dark:   #0a5d54;
  --color-accent:         #1a5fa8;
  --color-accent-light:   #4a86c8;
  --color-accent-dark:    #13467d;
  --gradient-brand:       linear-gradient(135deg, #0e7a6e 0%, #1aaa97 100%);
  --gradient-brand-hover: linear-gradient(135deg, #0a5d54 0%, #168f7f 100%);
  --gradient-brand-light: linear-gradient(135deg, rgba(14,122,110,.08) 0%, rgba(26,169,151,.08) 100%);
  --gradient-hero:        linear-gradient(135deg, #0e7a6e 0%, #168f7f 45%, #1aaa97 100%);

  /* — Neutral(米白纸感 + 棕色字)— */
  --color-bg:             #faf7f2;
  --color-bg-elevated:    #ffffff;
  --color-bg-muted:       #f4f0e8;
  --color-bg-overlay:     rgba(44, 36, 22, .45);
  --color-border:         #e2dace;
  --color-border-hover:   #cec5b4;
  --color-text:           #2c2416;
  --color-text-secondary: #6b5c44;
  --color-text-muted:     #a8977e;
  --color-text-inverse:   #ffffff;

  /* — Semantic(低饱和,贴纸感)— */
  --color-success:        #1a7f5a;
  --color-success-light:  #e3f1ea;
  --color-success-dark:   #136141;
  --color-warning:        #b05e10;
  --color-warning-light:  #f6e9d8;
  --color-warning-dark:   #87470c;
  --color-danger:         #c0394b;
  --color-danger-light:   #f6e0e3;
  --color-danger-dark:    #952b39;
  --color-info:           #1a5fa8;
  --color-info-light:     #e0eaf6;
  --color-info-dark:      #13467d;

  /* — Spacing (8px grid) — */
  --sp-0:  0;
  --sp-1:  4px;
  --sp-2:  8px;
  --sp-3:  12px;
  --sp-4:  16px;
  --sp-5:  20px;
  --sp-6:  24px;
  --sp-7:  28px;
  --sp-8:  32px;
  --sp-10: 40px;
  --sp-12: 48px;
  --sp-14: 56px;
  --sp-16: 64px;
  --sp-20: 80px;
  --sp-24: 96px;

  /* — Border radius — */
  --radius-sm:   6px;
  --radius-md:   10px;
  --radius-lg:   16px;
  --radius-xl:   20px;
  --radius-2xl:  24px;
  --radius-full: 9999px;

  /* — Shadows (multi-layer, 暖棕纸感)— */
  --shadow-sm:   0 1px 2px rgba(44,36,22,.04), 0 1px 3px rgba(44,36,22,.06);
  --shadow-md:   0 2px 4px rgba(44,36,22,.04), 0 4px 12px rgba(44,36,22,.08);
  --shadow-lg:   0 4px 8px rgba(44,36,22,.04), 0 8px 24px rgba(44,36,22,.10);
  --shadow-xl:   0 8px 16px rgba(44,36,22,.06), 0 16px 48px rgba(44,36,22,.12);
  --shadow-card: 0 1px 3px rgba(44,36,22,.04), 0 4px 16px rgba(44,36,22,.06);
  --shadow-card-hover: 0 4px 8px rgba(44,36,22,.06), 0 12px 32px rgba(44,36,22,.12);

  /* — Typography — */
  --font-sans:  'Inter', 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', system-ui, sans-serif;
  --font-mono:  'JetBrains Mono', 'Fira Code', 'Consolas', monospace;
  --fs-xs:   12px;
  --fs-sm:   13px;
  --fs-base: 14px;
  --fs-md:   15px;
  --fs-lg:   16px;
  --fs-xl:   18px;
  --fs-2xl:  20px;
  --fs-3xl:  24px;
  --fs-4xl:  28px;
  --fs-5xl:  32px;
  --fs-6xl:  40px;
  --lh-tight:  1.25;
  --lh-normal: 1.5;
  --lh-relaxed:1.65;

  /* — Transitions — */
  --ease-out:    cubic-bezier(.16, 1, .3, 1);
  --ease-in-out: cubic-bezier(.4, 0, .2, 1);
  --duration-fast:   .15s;
  --duration-normal: .2s;
  --duration-slow:   .3s;

  /* — Z-index layers — */
  --z-dropdown: 100;
  --z-sticky:   200;
  --z-overlay:  300;
  --z-modal:    400;
  --z-toast:    500;

  /* — Layout — */
  --nav-height:    64px;
  --container-max: 1200px;
  --container-narrow: 760px;
}

/* ============================================================
   Dark mode CSS variable overrides (reserved)
   ============================================================ */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    /* Uncomment when dark mode is fully implemented:
    --color-bg:           #0f172a;
    --color-bg-elevated:  #1e293b;
    --color-bg-muted:     #1a2332;
    --color-border:       #334155;
    --color-border-hover: #475569;
    --color-text:         #f1f5f9;
    --color-text-secondary:#94a3b8;
    --color-text-muted:   #64748b;
    --shadow-card: 0 1px 3px rgba(0,0,0,.2), 0 4px 16px rgba(0,0,0,.3);
    --shadow-card-hover: 0 4px 8px rgba(0,0,0,.3), 0 12px 32px rgba(0,0,0,.4);
    */
  }
}
/* Manual dark mode toggle: add data-theme="dark" to <html> */
[data-theme="dark"] {
  --color-bg:           #0f172a;
  --color-bg-elevated:  #1e293b;
  --color-bg-muted:     #1a2332;
  --color-border:       #334155;
  --color-border-hover: #475569;
  --color-text:         #f1f5f9;
  --color-text-secondary:#94a3b8;
  --color-text-muted:   #64748b;
  --color-bg-overlay:   rgba(0, 0, 0, .6);
  --shadow-card:  0 1px 3px rgba(0,0,0,.3), 0 4px 16px rgba(0,0,0,.4);
  --shadow-card-hover: 0 4px 8px rgba(0,0,0,.4), 0 12px 32px rgba(0,0,0,.5);
}

/* ============================================================
   2. RESET & BASE
   ============================================================ */
*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  font-size: var(--fs-base);
  line-height: var(--lh-normal);
  color: var(--color-text);
  background: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}

a {
  color: var(--color-primary);
  text-decoration: none;
  transition: color var(--duration-fast) var(--ease-in-out);
}
a:hover { color: var(--color-primary-dark); }

img, svg { display: block; max-width: 100%; }

button, input, select, textarea {
  font: inherit;
  color: inherit;
  border: none;
  outline: none;
  background: none;
}

button { cursor: pointer; }

ul, ol { list-style: none; }

/* Focus-visible ring */
:focus-visible {
  outline: 2px solid var(--color-primary);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

/* Selection */
::selection {
  background: rgba(99, 102, 241, .2);
  color: var(--color-text);
}

/* Scrollbar (webkit) */
::-webkit-scrollbar { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--color-border-hover); border-radius: var(--radius-full); }
::-webkit-scrollbar-thumb:hover { background: var(--color-text-muted); }

/* ============================================================
   3. UTILITY CLASSES
   ============================================================ */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--sp-6);
}
.container--narrow {
  max-width: var(--container-narrow);
}

.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  padding: 0; margin: -1px;
  overflow: hidden;
  clip: rect(0,0,0,0);
  white-space: nowrap;
  border: 0;
}

.text-gradient {
  background: var(--gradient-brand);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* ============================================================
   4. NAVIGATION BAR (.navbar)
   ============================================================ */
.navbar {
  position: sticky;
  top: 0;
  z-index: var(--z-sticky);
  height: var(--nav-height);
  background: var(--color-bg-elevated);
  border-bottom: 1px solid var(--color-border);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  background: rgba(255,255,255,.88);
}
[data-theme="dark"] .navbar {
  background: rgba(30,41,59,.88);
}

.navbar__inner {
  display: flex;
  align-items: center;
  gap: var(--sp-4);
  height: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: var(--sp-6);
}

.navbar__logo {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  font-size: var(--fs-xl);
  font-weight: 700;
  color: var(--color-text);
  white-space: nowrap;
  flex-shrink: 0;
}
.navbar__logo-icon {
  width: 32px; height: 32px;
  border-radius: var(--radius-md);
  background: var(--gradient-brand);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-size: var(--fs-lg);
  font-weight: 800;
}

.navbar__links {
  display: flex;
  align-items: center;
  gap: var(--sp-1);
}
.navbar__link {
  padding: var(--sp-2) var(--sp-3);
  font-size: var(--fs-base);
  font-weight: 500;
  color: var(--color-text-secondary);
  border-radius: var(--radius-md);
  transition: all var(--duration-fast) var(--ease-in-out);
  white-space: nowrap;
}
.navbar__link:hover {
  color: var(--color-primary);
  background: var(--gradient-brand-light);
}
.navbar__link--active {
  color: var(--color-primary);
  background: var(--gradient-brand-light);
}

/* Campus switcher */
.navbar__campus {
  position: relative;
  flex-shrink: 0;
}
.navbar__campus-btn {
  display: flex;
  align-items: center;
  gap: var(--sp-1);
  padding: var(--sp-2) var(--sp-3);
  font-size: var(--fs-sm);
  font-weight: 500;
  color: var(--color-text);
  background: var(--color-bg-muted);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  transition: all var(--duration-fast) var(--ease-in-out);
  white-space: nowrap;
}
.navbar__campus-btn:hover {
  border-color: var(--color-primary-light);
  background: var(--gradient-brand-light);
}
.navbar__campus-btn .arrow {
  font-size: 10px;
  transition: transform var(--duration-fast) var(--ease-in-out);
}
.navbar__campus.open .navbar__campus-btn .arrow {
  transform: rotate(180deg);
}
.navbar__campus-dropdown {
  position: absolute;
  top: calc(100% + var(--sp-2));
  left: 0;
  min-width: 180px;
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  padding: var(--sp-2);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-8px);
  transition: all var(--duration-normal) var(--ease-out);
  z-index: var(--z-dropdown);
}
.navbar__campus.open .navbar__campus-dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
.navbar__campus-option {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  padding: var(--sp-2) var(--sp-3);
  font-size: var(--fs-sm);
  border-radius: var(--radius-md);
  transition: background var(--duration-fast);
  cursor: pointer;
  white-space: nowrap;
}
.navbar__campus-option:hover {
  background: var(--color-bg-muted);
}
.navbar__campus-option--active {
  background: var(--gradient-brand-light);
  color: var(--color-primary);
  font-weight: 600;
}

/* Search bar */
.navbar__search {
  position: relative;
  flex: 1;
  max-width: 400px;
  min-width: 0;
}
.navbar__search-input {
  width: 100%;
  height: 40px;
  padding: 0 var(--sp-4) 0 var(--sp-10);
  font-size: var(--fs-sm);
  background: var(--color-bg-muted);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-full);
  transition: all var(--duration-fast) var(--ease-in-out);
}
.navbar__search-input::placeholder { color: var(--color-text-muted); }
.navbar__search-input:focus {
  background: var(--color-bg-elevated);
  border-color: var(--color-primary-light);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, .12);
}
.navbar__search-icon {
  position: absolute;
  left: var(--sp-3);
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-text-muted);
  pointer-events: none;
  font-size: var(--fs-md);
}

/* Navbar actions (right side) */
.navbar__actions {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  flex-shrink: 0;
}

.navbar__icon-btn {
  position: relative;
  width: 40px; height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-full);
  font-size: var(--fs-lg);
  color: var(--color-text-secondary);
  transition: all var(--duration-fast) var(--ease-in-out);
}
.navbar__icon-btn:hover {
  background: var(--color-bg-muted);
  color: var(--color-text);
}
.navbar__icon-btn .dot {
  position: absolute;
  top: 8px; right: 8px;
  width: 8px; height: 8px;
  background: var(--color-danger);
  border: 2px solid var(--color-bg-elevated);
  border-radius: var(--radius-full);
}

/* Points badge */
.navbar__points {
  display: flex;
  align-items: center;
  gap: var(--sp-1);
  padding: var(--sp-1) var(--sp-3);
  font-size: var(--fs-sm);
  font-weight: 600;
  color: var(--color-warning-dark);
  background: var(--color-warning-light);
  border-radius: var(--radius-full);
  white-space: nowrap;
}

/* User avatar + dropdown */
.navbar__user {
  position: relative;
}
.navbar__avatar {
  width: 36px; height: 36px;
  border-radius: var(--radius-full);
  background: var(--gradient-brand);
  display: flex;
  align-items: center;
  justify-content: center;
  color: #fff;
  font-weight: 700;
  font-size: var(--fs-sm);
  cursor: pointer;
  transition: box-shadow var(--duration-fast);
  border: 2px solid transparent;
}
.navbar__avatar:hover {
  box-shadow: 0 0 0 3px rgba(99,102,241,.2);
}
.navbar__user-dropdown {
  position: absolute;
  top: calc(100% + var(--sp-2));
  right: 0;
  min-width: 200px;
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  padding: var(--sp-2);
  opacity: 0;
  visibility: hidden;
  transform: translateY(-8px);
  transition: all var(--duration-normal) var(--ease-out);
  z-index: var(--z-dropdown);
}
.navbar__user.open .navbar__user-dropdown {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
.navbar__user-menu-header {
  padding: var(--sp-3);
  border-bottom: 1px solid var(--color-border);
  margin-bottom: var(--sp-2);
}
.navbar__user-menu-name {
  font-weight: 600;
  font-size: var(--fs-base);
}
.navbar__user-menu-email {
  font-size: var(--fs-xs);
  color: var(--color-text-muted);
  margin-top: 2px;
}
.navbar__user-menu-item {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  padding: var(--sp-2) var(--sp-3);
  font-size: var(--fs-sm);
  color: var(--color-text-secondary);
  border-radius: var(--radius-md);
  transition: all var(--duration-fast);
}
.navbar__user-menu-item:hover {
  background: var(--color-bg-muted);
  color: var(--color-text);
}
.navbar__user-menu-divider {
  height: 1px;
  background: var(--color-border);
  margin: var(--sp-2) 0;
}
.navbar__user-menu-item--danger { color: var(--color-danger); }
.navbar__user-menu-item--danger:hover {
  background: var(--color-danger-light);
  color: var(--color-danger-dark);
}

/* Auth buttons (logged out) */
.navbar__auth {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
}

/* Mobile hamburger */
.navbar__hamburger {
  display: none;
  width: 40px; height: 40px;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  font-size: var(--fs-xl);
  color: var(--color-text);
}

/* Mobile sidebar */
.navbar__mobile-menu {
  display: none;
  position: fixed;
  top: var(--nav-height);
  left: 0; right: 0; bottom: 0;
  background: var(--color-bg-elevated);
  z-index: var(--z-overlay);
  padding: var(--sp-4) var(--sp-6);
  overflow-y: auto;
  animation: slideDown var(--duration-normal) var(--ease-out);
}
.navbar__mobile-menu.open { display: block; }
.navbar__mobile-menu .navbar__link {
  display: block;
  padding: var(--sp-3) 0;
  font-size: var(--fs-lg);
  border-bottom: 1px solid var(--color-border);
  border-radius: 0;
}
.navbar__mobile-search {
  display: none;
  position: relative;
  margin-bottom: var(--sp-4);
}
.navbar__mobile-search .navbar__search-input {
  font-size: var(--fs-base);
  height: 44px;
}

@keyframes slideDown {
  from { opacity: 0; transform: translateY(-10px); }
  to   { opacity: 1; transform: translateY(0); }
}

/* ============================================================
   5. BUTTONS (.btn)
   ============================================================ */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-2);
  font-weight: 600;
  border-radius: var(--radius-full);
  transition: all var(--duration-fast) var(--ease-in-out);
  white-space: nowrap;
  cursor: pointer;
  user-select: none;
  position: relative;
  overflow: hidden;
  text-decoration: none;
  line-height: 1;
}

/* Variants */
.btn--primary {
  background: var(--gradient-brand);
  color: var(--color-text-inverse);
  box-shadow: 0 2px 8px rgba(99, 102, 241, .3);
}
.btn--primary:hover {
  background: var(--gradient-brand-hover);
  box-shadow: 0 4px 16px rgba(99, 102, 241, .4);
  transform: translateY(-1px);
}
.btn--primary:active {
  transform: translateY(0);
  box-shadow: 0 1px 4px rgba(99, 102, 241, .3);
}

.btn--ghost {
  background: transparent;
  color: var(--color-text-secondary);
  border: 1px solid var(--color-border);
}
.btn--ghost:hover {
  color: var(--color-text);
  border-color: var(--color-border-hover);
  background: var(--color-bg-muted);
}

.btn--accent {
  background: var(--color-accent);
  color: var(--color-text-inverse);
  box-shadow: 0 2px 8px rgba(6, 182, 212, .3);
}
.btn--accent:hover {
  background: var(--color-accent-dark);
  box-shadow: 0 4px 16px rgba(6, 182, 212, .4);
  transform: translateY(-1px);
}

.btn--danger {
  background: var(--color-danger);
  color: var(--color-text-inverse);
  box-shadow: 0 2px 8px rgba(239, 68, 68, .3);
}
.btn--danger:hover {
  background: var(--color-danger-dark);
  transform: translateY(-1px);
}

/* Sizes */
.btn--sm  { padding: 6px 14px;  font-size: var(--fs-xs); }
.btn--md  { padding: 10px 20px; font-size: var(--fs-sm); }
.btn--lg  { padding: 14px 28px; font-size: var(--fs-base); }

/* 提交 loading:防重复点击 + spinner */
.btn--loading { pointer-events: none; opacity: .7; }
.btn--loading::after {
  content: ''; display: inline-block; width: 14px; height: 14px; margin-left: 8px;
  border: 2px solid currentColor; border-top-color: transparent;
  border-radius: 50%; vertical-align: -2px; animation: btn-spin .6s linear infinite;
}
@keyframes btn-spin { to { transform: rotate(360deg); } }

/* Icon-only button */
.btn--icon {
  padding: 0;
  width: 40px; height: 40px;
  border-radius: var(--radius-full);
}
.btn--icon.btn--sm { width: 32px; height: 32px; }
.btn--icon.btn--lg { width: 48px; height: 48px; }

/* Loading state */
.btn--loading {
  pointer-events: none;
  opacity: .75;
}
.btn--loading .btn__spinner {
  display: inline-block;
  width: 16px; height: 16px;
  border: 2px solid transparent;
  border-top-color: currentColor;
  border-radius: var(--radius-full);
  animation: spin .6s linear infinite;
}
.btn__spinner { display: none; }
@keyframes spin { to { transform: rotate(360deg); } }

/* ============================================================
   6. CARDS (.card)
   ============================================================ */
.card {
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-card);
  overflow: hidden;
  transition: all var(--duration-normal) var(--ease-out);
}
.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-card-hover);
  border-color: var(--color-primary-light);
}

.card__body {
  padding: var(--sp-5);
}

.card__header {
  padding: var(--sp-5) var(--sp-5) 0;
}

.card__footer {
  padding: 0 var(--sp-5) var(--sp-5);
}

/* --- Resource card (material card) --- */
.card--resource {
  display: flex;
  flex-direction: column;
}
.card--resource .card__file-icon {
  width: 48px; height: 48px;
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-bg-muted);
  color: var(--color-text-secondary);
  flex-shrink: 0;
}
.card--resource .card__file-icon .ic { width: 24px; height: 24px; }
.card--resource .card__file-icon--pdf,
.card--resource .card__file-icon--doc,
.card--resource .card__file-icon--zip,
.card--resource .card__file-icon--img,
.card--resource .card__file-icon--ppt { color: #fff; }
.card--resource .card__file-icon--pdf  { background: #ef4444; }
.card--resource .card__file-icon--doc  { background: #3b82f6; }
.card--resource .card__file-icon--zip  { background: #f59e0b; }
.card--resource .card__file-icon--img  { background: #10b981; }
.card--resource .card__file-icon--ppt  { background: #ec4899; }

.card--resource .card__title {
  font-size: var(--fs-md);
  font-weight: 600;
  color: var(--color-text);
  line-height: var(--lh-tight);
  margin-top: var(--sp-3);
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}
.card--resource .card__title a {
  color: inherit;
}
.card--resource .card__title a:hover {
  color: var(--color-primary);
}

.card--resource .card__meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--sp-3);
  margin-top: var(--sp-3);
  font-size: var(--fs-xs);
  color: var(--color-text-muted);
}

.card--resource .card__bottom {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: var(--sp-4);
  padding-top: var(--sp-3);
  border-top: 1px solid var(--color-border);
}
.card--resource .card__author {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  font-size: var(--fs-xs);
  color: var(--color-text-secondary);
}
.card--resource .card__stats {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  font-size: var(--fs-xs);
  color: var(--color-text-muted);
}
.card--resource .card__stats span {
  display: flex;
  align-items: center;
  gap: 3px;
}
.card--resource .card__stats .ic { width: 13px; height: 13px; }

/* --- Category card --- */
.card--category {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--sp-5) var(--sp-4);
  text-align: center;
  cursor: pointer;
  min-height: 100px;
}
.card--category .card__emoji {
  font-size: 32px;
  margin-bottom: var(--sp-2);
}
.card--category .card__name {
  font-size: var(--fs-sm);
  font-weight: 600;
  color: var(--color-text);
}

/* --- Community feature card --- */
.card--community {
  display: flex;
  flex-direction: column;
  padding: var(--sp-6);
  text-align: center;
}
.card--community .card__emoji {
  font-size: 40px;
  margin-bottom: var(--sp-3);
}
.card--community .card__emoji .ic { width: 40px; height: 40px; }
.card--community .card__title {
  font-size: var(--fs-lg);
  font-weight: 700;
  margin-bottom: var(--sp-2);
}
.card--community .card__desc {
  font-size: var(--fs-sm);
  color: var(--color-text-secondary);
  line-height: var(--lh-relaxed);
  margin-bottom: var(--sp-4);
}

/* --- Stats card --- */
.card--stat {
  padding: var(--sp-6);
  text-align: center;
}
.card--stat .card__stat-value {
  font-size: var(--fs-4xl);
  font-weight: 800;
  background: var(--gradient-brand);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  line-height: 1.1;
}
.card--stat .card__stat-label {
  font-size: var(--fs-sm);
  color: var(--color-text-secondary);
  margin-top: var(--sp-1);
}

/* --- Detail card (large) --- */
.card--detail {
  padding: var(--sp-8);
}
.card--detail .card__detail-header {
  display: flex;
  gap: var(--sp-5);
  align-items: flex-start;
}
.card--detail .card__detail-icon {
  width: 64px; height: 64px;
  border-radius: var(--radius-xl);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 32px;
  flex-shrink: 0;
}
.card--detail .card__detail-title {
  font-size: var(--fs-2xl);
  font-weight: 700;
  line-height: var(--lh-tight);
}
.card--detail .card__detail-meta {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-4);
  margin-top: var(--sp-3);
  font-size: var(--fs-sm);
  color: var(--color-text-secondary);
}
.card--detail .card__detail-meta span {
  display: flex;
  align-items: center;
  gap: var(--sp-1);
}
.card--detail .card__detail-desc {
  margin-top: var(--sp-6);
  padding-top: var(--sp-6);
  border-top: 1px solid var(--color-border);
  font-size: var(--fs-base);
  line-height: var(--lh-relaxed);
  color: var(--color-text-secondary);
}
.card--detail .card__detail-actions {
  margin-top: var(--sp-6);
  display: flex;
  gap: var(--sp-3);
  align-items: center;
}

/* ============================================================
   7. FORM ELEMENTS (.form-*)
   ============================================================ */
.form-group {
  margin-bottom: var(--sp-5);
}
.form-label {
  display: block;
  font-size: var(--fs-sm);
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: var(--sp-2);
}
.form-label .required {
  color: var(--color-danger);
  margin-left: 2px;
}
.form-hint {
  font-size: var(--fs-xs);
  color: var(--color-text-muted);
  margin-top: var(--sp-1);
}

.form-input,
.form-textarea,
.form-select {
  width: 100%;
  padding: 10px var(--sp-4);
  font-size: var(--fs-base);
  background: var(--color-bg-elevated);
  border: 1.5px solid var(--color-border);
  border-radius: var(--radius-md);
  transition: all var(--duration-fast) var(--ease-in-out);
}
.form-input::placeholder,
.form-textarea::placeholder { color: var(--color-text-muted); }
.form-input:focus,
.form-textarea:focus,
.form-select:focus {
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, .1);
}
.form-textarea {
  min-height: 120px;
  resize: vertical;
  line-height: var(--lh-relaxed);
}
.form-select {
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' fill='%2364748b' viewBox='0 0 16 16'%3E%3Cpath d='M8 11.5l-5-5h10l-5 5z'/%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 36px;
  cursor: pointer;
}

/* Validation states */
.form-group--error .form-input,
.form-group--error .form-textarea,
.form-group--error .form-select {
  border-color: var(--color-danger);
  box-shadow: 0 0 0 3px rgba(239, 68, 68, .1);
}
.form-group--error .form-input:focus,
.form-group--error .form-textarea:focus {
  border-color: var(--color-danger);
  box-shadow: 0 0 0 3px rgba(239, 68, 68, .15);
}
.form-error {
  display: flex;
  align-items: center;
  gap: var(--sp-1);
  font-size: var(--fs-xs);
  color: var(--color-danger);
  margin-top: var(--sp-1);
}

.form-group--success .form-input,
.form-group--success .form-textarea,
.form-group--success .form-select {
  border-color: var(--color-success);
  box-shadow: 0 0 0 3px rgba(16, 185, 129, .1);
}
.form-success {
  display: flex;
  align-items: center;
  gap: var(--sp-1);
  font-size: var(--fs-xs);
  color: var(--color-success);
  margin-top: var(--sp-1);
}

/* ============================================================
   8. CHIPS / TAGS (.chip)
   ============================================================ */
.chip {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-1);
  padding: 6px 14px;
  font-size: var(--fs-xs);
  font-weight: 500;
  border-radius: var(--radius-full);
  border: 1px solid var(--color-border);
  background: var(--color-bg-elevated);
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all var(--duration-fast) var(--ease-in-out);
  white-space: nowrap;
}
.chip:hover {
  border-color: var(--color-primary-light);
  color: var(--color-primary);
  background: var(--gradient-brand-light);
}
.chip--active {
  background: var(--gradient-brand);
  color: var(--color-text-inverse);
  border-color: transparent;
}
.chip--active:hover {
  background: var(--gradient-brand-hover);
  color: var(--color-text-inverse);
}

/* ============================================================
   9. BADGES (.badge)
   ============================================================ */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 2px 8px;
  font-size: 11px;
  font-weight: 600;
  border-radius: var(--radius-full);
  line-height: 1.4;
}
.badge--primary  { background: rgba(99,102,241,.1);  color: var(--color-primary); }
.badge--success  { background: var(--color-success-light); color: var(--color-success-dark); }
.badge--warning  { background: var(--color-warning-light); color: var(--color-warning-dark); }
.badge--danger   { background: var(--color-danger-light);  color: var(--color-danger-dark); }
.badge--info     { background: var(--color-info-light);    color: var(--color-info-dark); }
.badge--accent   { background: rgba(6,182,212,.1);   color: var(--color-accent-dark); }

/* ============================================================
   10. AVATAR (.avatar)
   ============================================================ */
.avatar {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-full);
  font-weight: 700;
  background: var(--gradient-brand);
  color: #fff;
  flex-shrink: 0;
  line-height: 1;
}
.avatar--xs { width: 24px; height: 24px; font-size: 10px; }
.avatar--sm { width: 32px; height: 32px; font-size: 12px; }
.avatar--md { width: 40px; height: 40px; font-size: 14px; }
.avatar--lg { width: 56px; height: 56px; font-size: 18px; }
.avatar--xl { width: 72px; height: 72px; font-size: 24px; }

/* ============================================================
   11. PAGINATION (.pagination)
   ============================================================ */
.pagination {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-2);
  padding: var(--sp-6) 0;
}
.pagination__btn {
  min-width: 36px; height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--fs-sm);
  font-weight: 500;
  border-radius: var(--radius-md);
  border: 1px solid var(--color-border);
  background: var(--color-bg-elevated);
  color: var(--color-text-secondary);
  cursor: pointer;
  transition: all var(--duration-fast) var(--ease-in-out);
}
.pagination__btn:hover {
  border-color: var(--color-primary-light);
  color: var(--color-primary);
}
.pagination__btn--active {
  background: var(--gradient-brand);
  color: var(--color-text-inverse);
  border-color: transparent;
}
.pagination__btn--active:hover {
  background: var(--gradient-brand-hover);
  color: var(--color-text-inverse);
}
.pagination__btn:disabled {
  opacity: .4;
  cursor: not-allowed;
}

/* ============================================================
   12. TOAST (.toast)
   ============================================================ */
.toast-container {
  position: fixed;
  top: calc(var(--nav-height) + var(--sp-4));
  right: var(--sp-4);
  z-index: var(--z-toast);
  display: flex;
  flex-direction: column;
  gap: var(--sp-3);
  pointer-events: none;
}
.toast {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  padding: var(--sp-3) var(--sp-5);
  min-width: 300px;
  max-width: 420px;
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  font-size: var(--fs-sm);
  animation: toastIn var(--duration-slow) var(--ease-out);
  pointer-events: auto;
}
.toast--success { border-left: 4px solid var(--color-success); }
.toast--error   { border-left: 4px solid var(--color-danger); }
.toast--warning { border-left: 4px solid var(--color-warning); }
.toast--info    { border-left: 4px solid var(--color-info); }
.toast__icon {
  font-size: var(--fs-xl);
  flex-shrink: 0;
}
.toast__close {
  margin-left: auto;
  cursor: pointer;
  color: var(--color-text-muted);
  font-size: var(--fs-lg);
  padding: var(--sp-1);
}
.toast__close:hover { color: var(--color-text); }

@keyframes toastIn {
  from { opacity: 0; transform: translateX(40px); }
  to   { opacity: 1; transform: translateX(0); }
}
@keyframes toastOut {
  from { opacity: 1; transform: translateX(0); }
  to   { opacity: 0; transform: translateX(40px); }
}

/* ============================================================
   13. MODAL (.modal)
   ============================================================ */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: var(--color-bg-overlay);
  z-index: var(--z-modal);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--sp-6);
  opacity: 0;
  visibility: hidden;
  transition: all var(--duration-normal) var(--ease-in-out);
}
.modal-overlay.open {
  opacity: 1;
  visibility: visible;
}
.modal {
  width: 100%;
  max-width: 480px;
  background: var(--color-bg-elevated);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-xl);
  transform: scale(.95) translateY(10px);
  transition: transform var(--duration-normal) var(--ease-out);
}
.modal-overlay.open .modal {
  transform: scale(1) translateY(0);
}
.modal__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--sp-5) var(--sp-6);
  border-bottom: 1px solid var(--color-border);
}
.modal__title {
  font-size: var(--fs-lg);
  font-weight: 700;
}
.modal__close {
  width: 32px; height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  font-size: var(--fs-lg);
  color: var(--color-text-muted);
  transition: all var(--duration-fast);
}
.modal__close:hover {
  background: var(--color-bg-muted);
  color: var(--color-text);
}
.modal__body {
  padding: var(--sp-6);
}
.modal__footer {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: var(--sp-3);
  padding: var(--sp-4) var(--sp-6);
  border-top: 1px solid var(--color-border);
}

/* ============================================================
   14. EMPTY STATE (.empty-state)
   ============================================================ */
.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--sp-16) var(--sp-6);
  text-align: center;
}
.empty-state__icon {
  font-size: 64px;
  margin-bottom: var(--sp-5);
}
.empty-state__title {
  font-size: var(--fs-xl);
  font-weight: 700;
  margin-bottom: var(--sp-2);
}
.empty-state__desc {
  font-size: var(--fs-sm);
  color: var(--color-text-secondary);
  max-width: 400px;
  line-height: var(--lh-relaxed);
  margin-bottom: var(--sp-6);
}

/* ============================================================
   15. SKELETON (.skeleton)
   ============================================================ */
.skeleton {
  background: linear-gradient(
    90deg,
    var(--color-bg-muted) 25%,
    var(--color-border) 37%,
    var(--color-bg-muted) 63%
  );
  background-size: 400% 100%;
  animation: skeleton-shimmer 1.4s ease infinite;
  border-radius: var(--radius-md);
}
.skeleton--circle { border-radius: var(--radius-full); }
.skeleton--text   { height: 14px; margin-bottom: var(--sp-2); }
.skeleton--title  { height: 20px; width: 60%; margin-bottom: var(--sp-3); }
.skeleton--avatar { width: 40px; height: 40px; }
.skeleton--card   { height: 240px; }
.skeleton--rect   { height: 200px; }

@keyframes skeleton-shimmer {
  0%   { background-position: 100% 50%; }
  100% { background-position: 0 50%; }
}

/* ============================================================
   16. FOOTER (.footer)
   ============================================================ */
.footer {
  background: var(--color-bg-elevated);
  border-top: 1px solid var(--color-border);
  padding: var(--sp-12) 0 var(--sp-8);
  margin-top: var(--sp-16);
}
.footer__grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--sp-8);
}
.footer__brand-desc {
  font-size: var(--fs-sm);
  color: var(--color-text-secondary);
  line-height: var(--lh-relaxed);
  margin-top: var(--sp-3);
  max-width: 320px;
}
.footer__heading {
  font-size: var(--fs-sm);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--sp-4);
}
.footer__link {
  display: block;
  font-size: var(--fs-sm);
  color: var(--color-text-secondary);
  padding: var(--sp-1) 0;
  transition: color var(--duration-fast);
}
.footer__link:hover { color: var(--color-primary); }
.footer__bottom {
  margin-top: var(--sp-10);
  padding-top: var(--sp-6);
  border-top: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: space-between;
  font-size: var(--fs-xs);
  color: var(--color-text-muted);
}

/* ============================================================
   17. HERO SECTION (.hero)
   ============================================================ */
.hero {
  position: relative;
  background: var(--gradient-hero);
  padding: var(--sp-16) 0 var(--sp-14);
  overflow: hidden;
  text-align: center;
  color: #fff;
}
.hero__deco {
  position: absolute;
  border-radius: var(--radius-full);
  opacity: .15;
  pointer-events: none;
}
.hero__deco--1 {
  width: 300px; height: 300px;
  background: #fff;
  top: -80px; left: -60px;
  animation: float 6s ease-in-out infinite;
}
.hero__deco--2 {
  width: 200px; height: 200px;
  background: #fff;
  bottom: -40px; right: 10%;
  animation: float 8s ease-in-out infinite reverse;
}
.hero__deco--3 {
  width: 120px; height: 120px;
  background: #fff;
  top: 20%; right: 5%;
  animation: float 5s ease-in-out infinite 1s;
}
@keyframes float {
  0%, 100% { transform: translateY(0); }
  50%      { transform: translateY(-20px); }
}

.hero__title {
  font-size: var(--fs-5xl);
  font-weight: 800;
  line-height: var(--lh-tight);
  margin-bottom: var(--sp-4);
  position: relative;
}
.hero__subtitle {
  font-size: var(--fs-lg);
  opacity: .9;
  max-width: 520px;
  margin: 0 auto var(--sp-8);
  line-height: var(--lh-relaxed);
  position: relative;
}
.hero__search {
  display: flex;
  align-items: center;
  max-width: 520px;
  margin: 0 auto var(--sp-8);
  background: rgba(255,255,255,.15);
  backdrop-filter: blur(8px);
  border: 1px solid rgba(255,255,255,.25);
  border-radius: var(--radius-full);
  padding: var(--sp-1) var(--sp-1) var(--sp-1) var(--sp-5);
  position: relative;
}
.hero__search-input {
  flex: 1;
  background: none;
  border: none;
  color: #fff;
  font-size: var(--fs-base);
  padding: var(--sp-2) 0;
}
.hero__search-input::placeholder { color: rgba(255,255,255,.65); }
.hero__search-input:focus { outline: none; }
.hero__search-btn {
  padding: 10px 24px;
  background: #fff;
  color: var(--color-primary);
  font-weight: 600;
  font-size: var(--fs-sm);
  border-radius: var(--radius-full);
  transition: all var(--duration-fast);
  flex-shrink: 0;
}
.hero__search-btn:hover {
  background: rgba(255,255,255,.9);
  transform: scale(1.02);
}

.hero__ctas {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-3);
  margin-bottom: var(--sp-10);
  position: relative;
}
.hero__cta-secondary {
  background: rgba(255,255,255,.15);
  color: #fff;
  border: 1px solid rgba(255,255,255,.3);
}
.hero__cta-secondary:hover {
  background: rgba(255,255,255,.25);
  color: #fff;
  transform: translateY(-1px);
}
.hero__cta-primary {
  background: #fff;
  color: var(--color-primary);
  font-weight: 700;
}
.hero__cta-primary:hover {
  background: rgba(255,255,255,.92);
  color: var(--color-primary-dark);
  transform: translateY(-1px);
}

.hero__stats {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-10);
  position: relative;
}
.hero__stat-value {
  font-size: var(--fs-3xl);
  font-weight: 800;
  line-height: 1.1;
}
.hero__stat-label {
  font-size: var(--fs-sm);
  opacity: .75;
  margin-top: var(--sp-1);
}

/* ============================================================
   17b. LANDING(根域名多学校入口页)
   ============================================================ */
.landing {
  position: relative;
  padding: var(--sp-16) 0 var(--sp-12);
  text-align: center;
  overflow: hidden;
}
.landing__deco {
  position: absolute;
  border-radius: var(--radius-full);
  filter: blur(8px);
  opacity: .18;
  pointer-events: none;
}
.landing__deco--1 { width: 320px; height: 320px; top: -60px; left: -80px; background: var(--color-primary); }
.landing__deco--2 { width: 240px; height: 240px; bottom: -40px; right: -60px; background: var(--color-accent); }
.landing__eyebrow {
  display: inline-block;
  font-size: var(--fs-sm);
  font-weight: 600;
  color: var(--color-primary);
  background: color-mix(in srgb, var(--color-primary) 12%, transparent);
  padding: var(--sp-1) var(--sp-3);
  border-radius: var(--radius-full);
  margin-bottom: var(--sp-4);
}
.landing__title {
  font-size: var(--fs-5xl);
  font-weight: 800;
  line-height: 1.2;
  margin-bottom: var(--sp-4);
  background: var(--gradient-hero-text, linear-gradient(135deg, #0f766e, #3b82f6));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}
.landing__subtitle {
  font-size: var(--fs-lg);
  color: var(--color-text-secondary);
  max-width: 560px;
  margin: 0 auto var(--sp-8);
}
.landing__stats {
  display: flex;
  justify-content: center;
  gap: var(--sp-10);
  margin-bottom: var(--sp-10);
}
.landing__stat-value {
  font-size: var(--fs-3xl);
  font-weight: 800;
  color: var(--color-primary);
}
.landing__stat-label {
  font-size: var(--fs-sm);
  color: var(--color-text-muted);
  margin-top: var(--sp-1);
}
.landing__schools {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--sp-5);
  max-width: 760px;
  margin: 0 auto;
}
.landing__school {
  display: flex;
  align-items: center;
  gap: var(--sp-4);
  padding: var(--sp-5) var(--sp-5);
  background: var(--color-surface);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-lg);
  text-align: left;
  text-decoration: none;
  color: inherit;
  transition: transform .15s ease, box-shadow .15s ease, border-color .15s ease;
}
.landing__school:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  border-color: var(--school-color, var(--color-primary));
}
.landing__school-badge {
  flex-shrink: 0;
  width: 56px; height: 56px;
  border-radius: var(--radius-md);
  display: grid;
  place-items: center;
  font-size: var(--fs-2xl);
  font-weight: 800;
  color: #fff;
  background: var(--school-color, var(--color-primary));
}
.landing__school-body { flex: 1; min-width: 0; }
.landing__school-name {
  font-size: var(--fs-lg);
  font-weight: 700;
  margin-bottom: var(--sp-1);
}
.landing__school-meta {
  font-size: var(--fs-sm);
  color: var(--color-text-muted);
}
.landing__school-cta { flex-shrink: 0; }
.landing__footnote {
  margin-top: var(--sp-10);
  font-size: var(--fs-sm);
  color: var(--color-text-muted);
}
@media (max-width: 600px) {
  .landing { padding: var(--sp-10) 0 var(--sp-8); }
  .landing__title { font-size: var(--fs-3xl); }
  .landing__stats { gap: var(--sp-6); flex-wrap: wrap; }
  .landing__school { flex-wrap: wrap; }
}

/* ============================================================
   18. SECTION LAYOUT (.section)
   ============================================================ */
.section {
  padding: var(--sp-12) 0;
}
.section--flush { padding-top: 0; }   /* 连续 section 紧凑,替代行内 padding-top:0 */
.section__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--sp-6);
  gap: var(--sp-4);
}
.section__title {
  font-size: var(--fs-2xl);
  font-weight: 700;
}
.section__title-icon {
  margin-right: var(--sp-2);
}
.section__more {
  font-size: var(--fs-sm);
  font-weight: 500;
  color: var(--color-primary);
  white-space: nowrap;
}
.section__more:hover { color: var(--color-primary-dark); }

/* --- Category grid (horizontal scroll) --- */
.category-scroll {
  display: flex;
  gap: var(--sp-3);
  overflow-x: auto;
  padding-bottom: var(--sp-2);
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
}
.category-scroll::-webkit-scrollbar { height: 4px; }
.category-scroll .card--category {
  min-width: 110px;
  scroll-snap-align: start;
  flex-shrink: 0;
}

/* --- Card grid --- */
.card-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(270px, 1fr));
  gap: var(--sp-5);
}
.card-grid--sm {
  grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
  gap: var(--sp-4);
}
.card-grid--community {
  grid-template-columns: repeat(3, 1fr);
  gap: var(--sp-5);
}

/* --- Feedback / feed --- */
.feed-list {
  display: flex;
  flex-direction: column;
  gap: var(--sp-4);
}
.feed-item {
  display: flex;
  gap: var(--sp-4);
  padding: var(--sp-5);
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  transition: all var(--duration-fast);
}
.feed-item:hover {
  border-color: var(--color-primary-light);
  box-shadow: var(--shadow-sm);
}
.feed-item__content {
  flex: 1;
  min-width: 0;
}
.feed-item__header {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  margin-bottom: var(--sp-2);
}
.feed-item__name {
  font-weight: 600;
  font-size: var(--fs-sm);
}
.feed-item__time {
  font-size: var(--fs-xs);
  color: var(--color-text-muted);
}
.feed-item__text {
  font-size: var(--fs-sm);
  color: var(--color-text-secondary);
  line-height: var(--lh-relaxed);
}
.feed-item__actions {
  display: flex;
  gap: var(--sp-4);
  margin-top: var(--sp-3);
  font-size: var(--fs-xs);
  color: var(--color-text-muted);
}
.feed-item__action {
  display: flex;
  align-items: center;
  gap: var(--sp-1);
  cursor: pointer;
  transition: color var(--duration-fast);
}
.feed-item__action:hover { color: var(--color-primary); }

/* ============================================================
   19. DRAG-AND-DROP UPLOAD ZONE (.upload-zone)
   ============================================================ */
.upload-zone {
  border: 2px dashed var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--sp-10) var(--sp-6);
  text-align: center;
  cursor: pointer;
  transition: all var(--duration-normal) var(--ease-out);
  background: var(--color-bg-muted);
}
.upload-zone:hover,
.upload-zone.dragover {
  border-color: var(--color-primary);
  background: var(--gradient-brand-light);
}
.upload-zone__icon {
  font-size: 48px;
  margin-bottom: var(--sp-3);
}
.upload-zone__title {
  font-size: var(--fs-md);
  font-weight: 600;
  margin-bottom: var(--sp-1);
}
.upload-zone__hint {
  font-size: var(--fs-sm);
  color: var(--color-text-muted);
}
.upload-zone__hint b {
  color: var(--color-primary);
  font-weight: 600;
}
.upload-zone__files {
  margin-top: var(--sp-4);
  text-align: left;
}
.upload-file {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  padding: var(--sp-3);
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  margin-top: var(--sp-2);
}
.upload-file__icon {
  font-size: 20px;
  flex-shrink: 0;
}
.upload-file__info {
  flex: 1;
  min-width: 0;
}
.upload-file__name {
  font-size: var(--fs-sm);
  font-weight: 500;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.upload-file__size {
  font-size: var(--fs-xs);
  color: var(--color-text-muted);
}
.upload-file__remove {
  color: var(--color-text-muted);
  cursor: pointer;
  font-size: var(--fs-lg);
  transition: color var(--duration-fast);
}
.upload-file__remove:hover { color: var(--color-danger); }

/* ============================================================
   20. AUTH PAGE (.auth-page)
   ============================================================ */
.auth-page {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--sp-6);
  background: var(--color-bg);
}
.auth-card {
  display: flex;
  width: 100%;
  max-width: 900px;
  background: var(--color-bg-elevated);
  border-radius: var(--radius-2xl);
  box-shadow: var(--shadow-xl);
  overflow: hidden;
}
.auth-card__brand {
  flex: 1;
  background: var(--gradient-hero);
  padding: var(--sp-12);
  display: flex;
  flex-direction: column;
  justify-content: center;
  color: #fff;
  position: relative;
  overflow: hidden;
  min-height: 500px;
}
.auth-card__brand-deco {
  position: absolute;
  border-radius: var(--radius-full);
  opacity: .1;
  background: #fff;
  pointer-events: none;
}
.auth-card__brand-deco--1 {
  width: 200px; height: 200px;
  top: -40px; right: -40px;
  animation: float 7s ease-in-out infinite;
}
.auth-card__brand-deco--2 {
  width: 140px; height: 140px;
  bottom: 10%; left: -30px;
  animation: float 5s ease-in-out infinite 2s;
}
.auth-card__brand-title {
  font-size: var(--fs-3xl);
  font-weight: 800;
  margin-bottom: var(--sp-4);
  position: relative;
}
.auth-card__brand-subtitle {
  font-size: var(--fs-base);
  opacity: .85;
  line-height: var(--lh-relaxed);
  max-width: 300px;
  position: relative;
}
.auth-card__brand-features {
  margin-top: var(--sp-8);
  display: flex;
  flex-direction: column;
  gap: var(--sp-3);
  position: relative;
}
.auth-card__brand-feature {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  font-size: var(--fs-sm);
  opacity: .9;
}

.auth-card__form {
  flex: 1;
  padding: var(--sp-10) var(--sp-10);
  display: flex;
  flex-direction: column;
  justify-content: center;
}
.auth-card__form-title {
  font-size: var(--fs-2xl);
  font-weight: 700;
  margin-bottom: var(--sp-2);
}
.auth-card__form-subtitle {
  font-size: var(--fs-sm);
  color: var(--color-text-secondary);
  margin-bottom: var(--sp-8);
}
.auth-card__form-footer {
  text-align: center;
  font-size: var(--fs-sm);
  color: var(--color-text-secondary);
  margin-top: var(--sp-6);
}
.auth-card__form-footer a {
  font-weight: 600;
}

/* Password strength */
.password-strength {
  display: flex;
  gap: var(--sp-1);
  margin-top: var(--sp-2);
}
.password-strength__bar {
  flex: 1;
  height: 4px;
  border-radius: var(--radius-full);
  background: var(--color-border);
  transition: background var(--duration-fast);
}
.password-strength--weak .password-strength__bar:nth-child(1) { background: var(--color-danger); }
.password-strength--medium .password-strength__bar:nth-child(-n+2) { background: var(--color-warning); }
.password-strength--strong .password-strength__bar { background: var(--color-success); }
.password-strength__text {
  font-size: var(--fs-xs);
  margin-top: var(--sp-1);
}
.password-strength--weak .password-strength__text { color: var(--color-danger); }
.password-strength--medium .password-strength__text { color: var(--color-warning-dark); }
.password-strength--strong .password-strength__text { color: var(--color-success-dark); }

/* ============================================================
   21. SORT TABS (.sort-tabs)
   ============================================================ */
.sort-tabs {
  display: flex;
  align-items: center;
  gap: var(--sp-1);
  background: var(--color-bg-muted);
  border-radius: var(--radius-full);
  padding: var(--sp-1);
}
.sort-tab {
  padding: 6px 16px;
  font-size: var(--fs-sm);
  font-weight: 500;
  border-radius: var(--radius-full);
  color: var(--color-text-secondary);
  transition: all var(--duration-fast) var(--ease-in-out);
  cursor: pointer;
}
.sort-tab:hover {
  color: var(--color-text);
}
.sort-tab--active {
  background: var(--color-bg-elevated);
  color: var(--color-text);
  box-shadow: var(--shadow-sm);
}

/* ============================================================
   22. FILTER BAR (.filter-bar)
   ============================================================ */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-2);
  margin-bottom: var(--sp-5);
}

/* ============================================================
   23. BREADCRUMB
   ============================================================ */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  font-size: var(--fs-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--sp-6);
}
.breadcrumb__link {
  color: var(--color-text-secondary);
}
.breadcrumb__link:hover { color: var(--color-primary); }
.breadcrumb__sep { color: var(--color-text-muted); }
.breadcrumb__current { color: var(--color-text); font-weight: 500; }

/* ============================================================
   24. PASSWORD INPUT with toggle
   ============================================================ */
.password-input-wrapper {
  position: relative;
}
.password-input-wrapper .form-input {
  padding-right: 44px;
}
.password-toggle {
  position: absolute;
  right: var(--sp-3);
  top: 50%;
  transform: translateY(-50%);
  color: var(--color-text-muted);
  cursor: pointer;
  font-size: var(--fs-md);
}
.password-toggle:hover { color: var(--color-text); }

/* ============================================================
   25. INLINE ADD (for select with "new" option)
   ============================================================ */
.inline-add {
  display: flex;
  gap: var(--sp-2);
}
.inline-add .form-input,
.inline-add .form-select {
  flex: 1;
}

/* ============================================================
   26. RESULT COUNT
   ============================================================ */
.result-count {
  font-size: var(--fs-sm);
  color: var(--color-text-secondary);
  margin-bottom: var(--sp-4);
}
.result-count b {
  color: var(--color-primary);
  font-weight: 700;
}

/* ============================================================
   27. RESPONSIVE BREAKPOINTS
   ============================================================ */

/* Tablet (768-1024) */
@media (max-width: 1024px) {
  .navbar__links { display: none; }
  .navbar__hamburger { display: flex; }
  .navbar__mobile-menu .navbar__link { display: block; }
  .navbar__mobile-search { display: block; }
  .navbar__search { max-width: 280px; }

  .hero__title { font-size: var(--fs-4xl); }
  .hero__stats { gap: var(--sp-6); }

  .card-grid--community { grid-template-columns: repeat(2, 1fr); }
  .footer__grid { grid-template-columns: 1fr 1fr; gap: var(--sp-6); }

  .auth-card__brand { padding: var(--sp-8); }
  .auth-card__form { padding: var(--sp-8); }
}

/* Mobile (<768) */
@media (max-width: 768px) {
  :root {
    --nav-height: 56px;
  }
  .navbar__search { display: none; }
  .navbar__campus { display: none; }
  .navbar__points { display: none; }
  .navbar__inner { padding-inline: var(--sp-4); }

  .hero { padding: var(--sp-10) 0 var(--sp-8); }
  .hero__title { font-size: var(--fs-3xl); }
  .hero__subtitle { font-size: var(--fs-base); }
  .hero__search {
    flex-direction: column;
    padding: var(--sp-3);
    border-radius: var(--radius-xl);
  }
  .hero__search-input {
    width: 100%;
    text-align: center;
  }
  .hero__search-btn { width: 100%; text-align: center; }
  .hero__stats { flex-direction: column; gap: var(--sp-4); }
  .hero__ctas { flex-direction: column; }
  .hero__ctas .btn { width: 100%; }

  .card-grid { grid-template-columns: 1fr; }
  .card-grid--community { grid-template-columns: 1fr; }
  .card-grid--sm { grid-template-columns: repeat(2, 1fr); }

  .section { padding: var(--sp-8) 0; }
  .section__title { font-size: var(--fs-xl); }

  .footer__grid {
    grid-template-columns: 1fr;
    gap: var(--sp-6);
  }
  .footer__bottom {
    flex-direction: column;
    gap: var(--sp-2);
    text-align: center;
  }

  .auth-card {
    flex-direction: column;
  }
  .auth-card__brand {
    min-height: auto;
    padding: var(--sp-8) var(--sp-6);
  }
  .auth-card__form {
    padding: var(--sp-6);
  }

  .card--detail .card__detail-header {
    flex-direction: column;
    align-items: center;
    text-align: center;
  }
  .card--detail .card__detail-meta {
    justify-content: center;
  }
  .card--detail .card__detail-actions {
    flex-direction: column;
  }
  .card--detail .card__detail-actions .btn { width: 100%; }

  .filter-bar { gap: var(--sp-2); }
  .pagination__btn { min-width: 32px; height: 32px; font-size: var(--fs-xs); }
}

/* ============================================================
   28. PRINT STYLES
   ============================================================ */
@media print {
  .navbar, .footer, .hero__deco, .btn, .toast-container { display: none !important; }
  body { background: #fff; color: #000; }
  .card { box-shadow: none; border: 1px solid #ccc; break-inside: avoid; }
}

/* ============================================================
   29. 暨了么风 · Mono 功能标签 + 纸感润色
   内容是中文校园语气,功能信息(导航/标签/统计/时间/section label)用 Mono 工具感
   ============================================================ */
.navbar__link,
.footer__heading,
.badge,
.tag,
.chip,
.level-badge,
.school-tag,
.review-card__time,
.feed-item__time,
.breadcrumb,
.card__stats,
.stat__num,
.section-label {
  font-family: var(--font-mono);
}

/* section 标题左侧用青绿竖线,贴纸感卡片 */
.section__title { letter-spacing: .2px; }

/* 主按钮品牌色实心 */
.btn--primary {
  background: var(--gradient-brand);
  color: #fff;
}
.btn--primary:hover { background: var(--gradient-brand-hover); }

/* 导航 active 用青绿底线(原 token 已换,补底线视觉) */
.navbar__link--active {
  color: var(--color-primary);
}

/* 卡片 hover 暖色描边 */
.card:hover {
  border-color: var(--color-border-hover);
}

/* 贡献榜(footer) */
.contrib-board {
  background: var(--color-bg-muted);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--sp-5);
  margin-top: var(--sp-5);
}
.contrib-board__title {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  letter-spacing: 1.5px;
  text-transform: uppercase;
  color: var(--color-text-muted);
  margin-bottom: var(--sp-3);
  display: flex;
  align-items: center;
  gap: var(--sp-2);
}
.contrib-board__title::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--color-border);
}
.contrib-board__list {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
  gap: var(--sp-2);
}
.contrib-item {
  display: flex;
  align-items: center;
  gap: var(--sp-2);
  padding: var(--sp-2);
  border-radius: var(--radius-md);
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border);
}
.contrib-item__rank {
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
  font-weight: 700;
  color: var(--color-text-muted);
  min-width: 22px;
}
.contrib-item:nth-child(1) .contrib-item__rank { color: var(--color-warning); }
.contrib-item:nth-child(2) .contrib-item__rank { color: var(--color-text-muted); }
.contrib-item:nth-child(3) .contrib-item__rank { color: #b07a2e; }
.contrib-item__name {
  font-weight: 600;
  color: var(--color-text);
  font-size: var(--fs-sm);
  flex: 1;
  min-width: 0;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.contrib-item__pts {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  color: var(--color-primary);
  font-weight: 700;
}

/* 提示/免责条(左竖线强调) */
.notice {
  background: var(--color-bg-muted);
  border: 1px solid var(--color-border);
  border-left: 3px solid var(--color-primary);
  border-radius: var(--radius-md);
  padding: var(--sp-3) var(--sp-4);
  font-size: var(--fs-sm);
  color: var(--color-text-secondary);
  line-height: 1.65;
}
.footer__disclaimer {
  text-align: center;
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  color: var(--color-text-muted);
  padding: var(--sp-4) var(--sp-3) 0;
  line-height: 1.7;
}

/* 二手物品卡 */
.item-card { padding: var(--sp-4); transition: border-color var(--duration-fast), transform var(--duration-fast); }
.item-card:hover { border-color: var(--color-primary); transform: translateY(-2px); }
.item-card__row { display: flex; align-items: center; gap: var(--sp-4); }
.item-card__title { font-size: var(--fs-md); font-weight: 700; color: var(--color-text); margin-bottom: var(--sp-1); display: flex; align-items: center; gap: var(--sp-2); }
.item-card__meta { display: flex; align-items: center; gap: var(--sp-2); flex-wrap: wrap; margin-bottom: var(--sp-2); }
.item-card__cond { font-family: var(--font-mono); font-size: var(--fs-xs); color: var(--color-text-muted); }
.item-card__desc { font-size: var(--fs-sm); color: var(--color-text-secondary); line-height: 1.6; display: -webkit-box; -webkit-line-clamp: 2; -webkit-box-orient: vertical; overflow: hidden; margin: 0 0 var(--sp-2); }
.item-card__foot { display: flex; align-items: center; gap: var(--sp-2); font-family: var(--font-mono); font-size: var(--fs-xs); color: var(--color-text-muted); }
.item-card__seller { color: var(--color-text-secondary); font-weight: 600; }
.item-card__price { font-family: var(--font-mono); font-weight: 800; font-size: var(--fs-lg); color: var(--color-primary); white-space: nowrap; }
.item-card__price--lg { font-size: var(--fs-xl); }
.badge--muted { background: var(--color-bg-muted); color: var(--color-text-muted); border: 1px solid var(--color-border); }
.badge--success { background: var(--color-success-light); color: var(--color-success-dark); border: 1px solid var(--color-success); }