/* ============================================================
   MAIN — homepage + shared components (header / footer / modal / form)
   依赖 assets/tokens.css 和 assets/base.css
   ============================================================ */

/* ============ HEADER / NAV ============ */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--header-height);
  background: rgba(12, 20, 139, 0.9);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}

.nav-wrap {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--header-height);
  gap: var(--space-4);
}

.logo {
  font-weight: var(--fw-bold);
  font-size: 26px;
  letter-spacing: 0.5px;
  color: var(--yellow);
  flex-shrink: 0;
}

.site-nav {
  display: flex;
  gap: var(--space-5);
  align-items: center;
  margin-left: auto;
}

.site-nav a {
  color: var(--muted);
  font-size: var(--font-h4);
  transition: color 0.2s;
}

.site-nav a:hover {
  color: var(--text);
}

.lang-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: transparent;
  border: 1px solid var(--border);
  cursor: pointer;
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-btn);
  font-size: var(--font-small);
  font-family: inherit;
  color: var(--muted);
  transition: background 0.2s, border-color 0.2s, color 0.2s;
  line-height: 1.2;
}

.lang-btn:hover {
  background: rgba(255, 255, 255, 0.06);
  border-color: var(--accent);
  color: var(--text);
}

.nav-toggle,
.nav-toggle-label {
  display: none;
}

/* ============ HERO ============ */
.hero {
  padding: var(--space-9) 0 var(--space-8);
  text-align: center;
  background: radial-gradient(ellipse at top, #1622ae 0%, var(--bg) 65%);
}

.hero-title {
  font-size: var(--font-hero);
  margin-bottom: var(--space-3);
  color: var(--yellow);
  line-height: 1.1;
}

.hero-sub {
  color: var(--muted);
  font-size: var(--font-h4);
  margin-bottom: var(--space-6);
}

/* ============ SECTIONS ============ */
.section {
  padding: var(--space-6) 0;
}

.section-title {
  font-size: var(--font-h1);
  text-align: center;
  margin-bottom: var(--space-5);
  color: var(--text);
}

.section-body {
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
  color: var(--muted);
  font-size: var(--font-body);
  line-height: var(--lh-body);
}

/* ============ POST LIST (category section on home) ============ */
.post-list {
  list-style: none;
  margin-top: var(--space-5);
}

.post-item {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: var(--space-4);
  padding: var(--space-4) 0;
  border-bottom: 1px solid var(--border);
  transition: padding-left 0.2s;
}

.post-item:hover {
  padding-left: var(--space-2);
}

.post-title-link {
  color: var(--text);
  flex: 1;
  min-width: 0;
}

.post-title-link:hover .post-title {
  color: var(--accent);
}

.post-title {
  font-weight: var(--fw-semibold);
  font-size: var(--font-h4);
  line-height: 1.3;
}

.post-meta {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  flex-shrink: 0;
  font-size: var(--font-small);
  white-space: nowrap;
}

.post-author {
  color: var(--accent);
  transition: color 0.2s;
}

.post-author:hover {
  color: var(--accent-hover);
  text-decoration: underline;
}

.post-sep {
  color: var(--muted);
  opacity: 0.6;
}

.post-date {
  color: var(--muted);
}

/* ============ VISIBILITY BADGE ============ */
.post-badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  font-size: 0.85em;
  font-weight: var(--fw-semibold);
  padding: 2px 8px;
  border-radius: var(--radius-full);
  white-space: nowrap;
  vertical-align: middle;
  margin-left: 8px;
  line-height: 1.4;
}

.post-badge.members {
  color: #b45309;
  background: #fef3c7;
  border: 1px solid #fcd34d;
}

.post-badge.private {
  color: #7f1d1d;
  background: #fee2e2;
  border: 1px solid #fca5a5;
}

.post-badge.draft {
  color: #78350f;
  background: #fef3c7;
  border: 1px solid #fcd34d;
}

@media (max-width: 640px) {
  .post-item {
    align-items: flex-start;
    gap: var(--space-3);
  }

  .post-meta {
    flex-direction: column;
    align-items: flex-end;
    gap: 2px;
    white-space: normal;
  }

  .post-sep {
    display: none;
  }
}

/* ============ BUTTONS ============ */
.btn {
  display: inline-block;
  padding: var(--space-4) var(--space-6);
  border-radius: var(--radius-btn);
  font-weight: var(--fw-semibold);
  font-size: var(--font-body);
  font-family: inherit;
  transition: all 0.2s;
  border: 1px solid transparent;
  cursor: pointer;
  text-align: center;
}

.btn-primary {
  background-color: var(--accent);
  color: #0a1069;
  border-color: var(--accent);
}

.btn-primary:hover {
  background-color: var(--accent-hover);
  border-color: var(--accent-hover);
}

.btn-outline {
  background-color: transparent;
  color: var(--text);
  border-color: var(--text);
}

.btn-outline:hover {
  background-color: rgba(255, 255, 255, 0.1);
}

/* ============ MODAL ============ */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.7);
  -webkit-backdrop-filter: blur(4px);
  backdrop-filter: blur(4px);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 9999;
  padding: var(--space-5);
  overflow-y: auto;
}

.modal-overlay.open {
  display: flex;
}

.modal-box {
  position: relative;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: var(--space-6);
  max-width: 640px;
  width: 100%;
  max-height: 90vh;
  overflow-y: auto;
  box-shadow: var(--shadow-lg);
}

.modal-box h2 {
  font-size: var(--font-h3);
  margin-bottom: var(--space-5);
  color: var(--text);
}

.modal-close {
  position: absolute;
  top: var(--space-3);
  right: var(--space-4);
  background: transparent;
  border: none;
  color: var(--muted);
  font-size: 32px;
  line-height: 1;
  cursor: pointer;
  padding: var(--space-1) var(--space-2);
  border-radius: var(--radius-sm);
  transition: color 0.2s, background 0.2s;
}

.modal-close:hover {
  color: var(--text);
  background: rgba(255, 255, 255, 0.08);
}

/* ============ FORMS ============ */
.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-4);
}

.form-group {
  margin-bottom: var(--space-4);
}

.form-group label {
  display: block;
  font-size: var(--font-small);
  color: var(--muted);
  margin-bottom: var(--space-2);
}

.form-group input,
.form-group textarea,
.form-group select {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  font-size: var(--font-small);
  font-family: inherit;
  background: #ffffff;
  color: #0a1069;
  border: 1px solid #d0d8ff;
  border-radius: var(--radius-sm);
  outline: none;
  transition: border-color 0.2s, border-width 0.2s;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
  border-color: #ff4d6d;
  border-width: 3px;
  padding: calc(var(--space-3) - 2px) calc(var(--space-4) - 2px);
}

.form-group textarea {
  resize: vertical;
  min-height: 120px;
}

.form-actions {
  display: flex;
  gap: var(--space-3);
  margin-top: var(--space-5);
  flex-wrap: wrap;
  justify-content: center;
}

.form-note {
  margin-top: var(--space-3);
  font-size: var(--font-small);
  text-align: center;
  min-height: 1.2em;
}

.form-note.error {
  color: #ff7b8a;
}

.form-note.success {
  color: #7ff0b3;
}

.captcha-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-3);
  flex-wrap: wrap;
}

.captcha-label {
  color: var(--muted);
  font-size: var(--font-small);
  margin: 0;
  white-space: nowrap;
}

.captcha-question {
  color: var(--yellow);
  font-weight: var(--fw-semibold);
  font-size: var(--font-small);
  white-space: nowrap;
}

.captcha-input {
  width: 100px;
  text-align: center;
  font-size: var(--font-small);
  font-family: inherit;
  padding: var(--space-2) var(--space-3);
  background: #ffffff;
  color: #0a1069;
  border: 1px solid #d0d8ff;
  border-radius: var(--radius-sm);
  outline: none;
  transition: border-color 0.2s, border-width 0.2s;
}

.captcha-input:focus {
  border-color: #ff4d6d;
  border-width: 3px;
  padding: calc(var(--space-2) - 2px) calc(var(--space-3) - 2px);
}

/* ============ FOOTER ============ */
.site-footer {
  border-top: 1px solid var(--border);
  padding: var(--space-6) 0;
  background: var(--bg-alt);
  text-align: center;
}

.footer-copy {
  color: var(--muted);
  font-size: var(--font-small);
}

/* ============ BACK TO TOP ============ */
.to-top {
  position: fixed;
  right: 28px;
  bottom: 28px;
  z-index: 50;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  border: 2px solid #0c148b;
  cursor: pointer;
  background: #ffffff;
  color: #0c148b;
  display: grid;
  place-items: center;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.3);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s, transform 0.25s, box-shadow 0.25s, background 0.25s, color 0.25s;
  -webkit-tap-highlight-color: transparent;
}

.to-top.show {
  opacity: 1;
  pointer-events: auto;
}

@media (hover: hover) and (pointer: fine) {
  .to-top.show:hover {
    background: #ffd83d;
    color: #0c148b;
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.4);
  }
}

.to-top.show.pressed,
.to-top.show:active {
  background: #ffd83d;
  color: #0c148b;
  transform: translateY(-1px);
}

@media (max-width: 640px) {
  .to-top {
    width: 42px;
    height: 42px;
    right: 18px;
    bottom: 18px;
  }
}

/* ============ RESPONSIVE ============ */
@media (max-width: 900px) {
  .site-nav {
    position: fixed;
    top: var(--header-height);
    right: 0;
    min-width: 240px;
    background: var(--bg-alt);
    border-left: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
    border-radius: 0 0 0 var(--radius);
    flex-direction: column;
    align-items: flex-end;
    gap: 0;
    padding: 0;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s;
  }

  .site-nav a {
    padding: var(--space-3) var(--space-5);
    border-bottom: 1px solid var(--border);
    width: 100%;
    text-align: right;
    font-size: var(--font-small);
  }

  .lang-btn {
    order: 2;
    margin: 0 var(--space-3);
  }

  .nav-toggle-label {
    display: block;
    cursor: pointer;
    padding: var(--space-2);
    order: 3;
  }

  .nav-toggle-label span,
  .nav-toggle-label span::before,
  .nav-toggle-label span::after {
    display: block;
    background-color: var(--text);
    height: 2px;
    width: 30px;
    position: relative;
    transition: 0.3s;
  }

  .nav-toggle-label span::before,
  .nav-toggle-label span::after {
    content: "";
    position: absolute;
  }

  .nav-toggle-label span::before {
    top: -10px;
  }

  .nav-toggle-label span::after {
    top: 10px;
  }

  .nav-toggle:checked~.site-nav {
    max-height: calc(100vh - var(--header-height) - 64px);
    overflow-y: auto;
  }
}

@media (max-width: 640px) {
  :root {
    --header-height: 64px;
  }

  .hero {
    padding: var(--space-8) 0 var(--space-7);
  }

  .section {
    padding: var(--space-6) 0;
  }

  .form-row {
    grid-template-columns: 1fr;
  }

  .modal-box {
    padding: var(--space-5);
  }

  .nav-wrap {
    position: relative;
  }

  .logo {
    order: 1;
  }

  .lang-btn {
    order: 2;
    margin-left: auto;
    margin-right: var(--space-2);
  }

  .nav-toggle-label {
    order: 3;
  }

  .site-nav {
    order: 4;
  }
}