/*
 * DanmuAI 官网 — 布局样式
 * 导航栏、Section 通用、页脚
 */

/* ─── 容器 ─── */
.site-container {
  max-width: 72rem;
  margin-left: auto;
  margin-right: auto;
  padding-left: 1rem;
  padding-right: 1rem;
}

@media (min-width: 640px) {
  .site-container {
    padding-left: 1.5rem;
    padding-right: 1.5rem;
  }
}

@media (min-width: 1024px) {
  .site-container {
    padding-left: 2rem;
    padding-right: 2rem;
  }
}

/* ─── 导航栏 ─── */
.site-nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 50;
  height: var(--nav-height);
  display: flex;
  align-items: center;
  transition: background-color 0.3s, border-color 0.3s, backdrop-filter 0.3s;
  background-color: transparent;
  border-bottom: 1px solid transparent;
}

.site-nav.nav-scrolled {
  background-color: rgba(253, 251, 247, 0.85);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom-color: var(--border);
}

[data-theme="dark"] .site-nav.nav-scrolled {
  background-color: rgba(28, 25, 23, 0.85);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  max-width: 72rem;
  margin: 0 auto;
  padding: 0 1rem;
}

@media (min-width: 640px) {
  .nav-inner { padding: 0 1.5rem; }
}

@media (min-width: 1024px) {
  .nav-inner { padding: 0 2rem; }
}

/* Logo */
.nav-logo {
  display: flex;
  align-items: center;
  gap: 0.65rem;
  text-decoration: none;
  color: var(--color-text);
  font-weight: 700;
  font-size: 1.25rem;
}

.nav-logo-icon {
  width: 2.25rem;
  height: 2.25rem;
  background-color: var(--color-secondary);
  border-radius: 9999px;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-primary-hover);
  flex-shrink: 0;
}

.nav-logo-icon svg {
  width: 1.25rem;
  height: 1.25rem;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  stroke-linejoin: round;
  fill: none;
}

/* Nav links */
.nav-links {
  display: none;
  align-items: center;
  gap: 0.25rem;
}

@media (min-width: 768px) {
  .nav-links {
    display: flex;
  }
}

.nav-link {
  padding: 0.5rem 0.85rem;
  border-radius: var(--radius-md);
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--color-text);
  text-decoration: none;
  transition: background-color 0.2s, color 0.2s;
}

.nav-link:hover {
  background-color: var(--color-secondary);
  color: var(--color-primary-hover);
}

/* Nav actions (theme toggle) */
.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* Hamburger */
.nav-hamburger {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  background: var(--color-surface);
  cursor: pointer;
  color: var(--color-text);
  transition: border-color 0.2s;
}

.nav-hamburger:hover {
  border-color: var(--color-primary);
}

.nav-hamburger svg {
  width: 1.25rem;
  height: 1.25rem;
  stroke: currentColor;
  stroke-width: 2;
  stroke-linecap: round;
  fill: none;
}

@media (min-width: 768px) {
  .nav-hamburger {
    display: none;
  }
}

/* Mobile menu overlay */
.mobile-menu {
  position: fixed;
  inset: 0;
  z-index: 40;
  background-color: var(--color-bg);
  display: flex;
  flex-direction: column;
  padding: 5rem 2rem 2rem;
  transform: translateX(100%);
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.mobile-menu.mobile-menu-open {
  transform: translateX(0);
}

.mobile-menu .mobile-link {
  display: block;
  padding: 1rem 0;
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--color-text);
  text-decoration: none;
  border-bottom: 1px solid var(--border);
}

.mobile-menu .mobile-link:hover {
  color: var(--color-primary-hover);
}

@media (min-width: 768px) {
  .mobile-menu {
    display: none !important;
  }
}

/* ─── Section 通用 ─── */
.site-section {
  padding-top: 5rem;
  padding-bottom: 5rem;
}

@media (min-width: 768px) {
  .site-section {
    padding-top: 6rem;
    padding-bottom: 6rem;
  }
}

.section-title {
  font-size: 1.875rem;
  font-weight: 700;
  text-align: center;
  margin-bottom: 1rem;
  color: var(--color-text);
}

@media (min-width: 768px) {
  .section-title {
    font-size: 2.25rem;
  }
}

.section-subtitle {
  text-align: center;
  color: var(--color-text-dim);
  max-width: 40rem;
  margin: 0 auto 3rem;
  font-size: 1.05rem;
}

/* Hero 特殊 padding */
.section-hero {
  padding-top: calc(var(--nav-height) + 3rem);
  padding-bottom: 4rem;
  position: relative;
  overflow: hidden;
}

@media (min-width: 768px) {
  .section-hero {
    padding-top: calc(var(--nav-height) + 5rem);
    padding-bottom: 6rem;
  }
}

/* ─── 页脚 ─── */
.site-footer {
  background-color: var(--color-bg-subtle);
  border-top: 1px solid var(--border);
  padding: 3rem 0 2rem;
}

.footer-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 2rem;
  margin-bottom: 2rem;
}

@media (min-width: 640px) {
  .footer-grid {
    grid-template-columns: repeat(3, 1fr);
  }
}

.footer-heading {
  font-weight: 700;
  font-size: 0.875rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--color-text);
  margin-bottom: 0.75rem;
}

.footer-link {
  display: block;
  padding: 0.25rem 0;
  font-size: 0.875rem;
  color: var(--color-text-dim);
  text-decoration: none;
  transition: color 0.2s;
}

.footer-link:hover {
  color: var(--color-primary-hover);
}

.footer-bottom {
  border-top: 1px solid var(--border);
  padding-top: 1.5rem;
  text-align: center;
  font-size: 0.8125rem;
  color: var(--color-text-dim);
}