/* ============================================
   鹿谷社区官网 - 样式表
   主色 #2e6196 | 背景 #e6eff8 | 极简无渐变
   支持浅色/深色模式切换
   ============================================ */

/* --- CSS Variables (Light / Default) --- */
:root {
  --primary: #2e6196;
  --primary-dark: #234d78;
  --primary-light: #3d7ab8;
  --bg: #e6eff8;
  --bg-white: #ffffff;
  --text: #1a1a2e;
  --text-secondary: #5a6070;
  --text-muted: #8b92a4;
  --border: #d0dae8;
  --border-light: #e8eef5;
  --card-shadow: 0 1px 3px rgba(46,97,150,.06), 0 1px 2px rgba(0,0,0,.03);
  --card-hover-shadow: 0 4px 12px rgba(46,97,150,.10), 0 2px 4px rgba(0,0,0,.04);
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 20px;

  /* Typography - 系统字体栈，零网络请求 */
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Helvetica, Arial, sans-serif;
  --font-mono: "SF Mono", SFMono-Regular, Consolas, "Liberation Mono", Menlo, monospace;

  /* Spacing */
  --section-py: 80px;
  --container-max: 1140px;

  /* Transitions */
  --transition: .2s ease;

  /* Header */
  --header-bg: rgba(255,255,255,.92);
  --header-bg-scrolled: rgba(255,255,255,.96);
  --nav-mobile-bg: rgba(255,255,255,.98);
  --footer-bg: #1a1a2e;

  /* Theme */
  color-scheme: light;
}

/* --- CSS Variables (Dark Mode) --- */
[data-theme="dark"] {
  --primary: #4d90d9;
  --primary-dark: #3d7ab8;
  --primary-light: #5ba0e8;
  --bg: #0f1620;
  --bg-white: #1a2332;
  --text: #e2e8f0;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --border: #2d3a4f;
  --border-light: #233040;
  --card-shadow: 0 1px 3px rgba(0,0,0,.15), 0 1px 2px rgba(0,0,0,.08);
  --card-hover-shadow: 0 4px 12px rgba(0,0,0,.25), 0 2px 4px rgba(0,0,0,.10);

  --header-bg: rgba(15,22,32,.92);
  --header-bg-scrolled: rgba(15,22,32,.96);
  --nav-mobile-bg: rgba(15,22,32,.98);
  --footer-bg: #0a0f16;

  color-scheme: dark;
}

/* --- Reset & Base --- */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 72px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font);
  font-size: 16px;
  line-height: 1.7;
  color: var(--text);
  background-color: var(--bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

a {
  color: var(--primary);
  text-decoration: none;
  transition: color var(--transition);
}
a:hover {
  color: var(--primary-dark);
}

/* --- Container --- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 20px;
}

/* --- Section Base --- */
.section {
  padding: var(--section-py) 0;
}

.section-title {
  font-size: 32px;
  font-weight: 700;
  letter-spacing: -.02em;
  text-align: center;
  margin-bottom: 8px;
  color: var(--text);
}

.section-subtitle {
  font-size: 16px;
  line-height: 1.8;
  color: var(--text-secondary);
  text-align: center;
  margin-bottom: 48px;
  max-width: 680px;
  margin-left: auto;
  margin-right: auto;
}

/* ============================================
   Header / Navigation
   ============================================ */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: var(--header-bg);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: border-color var(--transition), background var(--transition);
}

.header.scrolled {
  border-bottom-color: var(--border);
  background: var(--header-bg-scrolled);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.logo-link {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--text);
  font-weight: 600;
  font-size: 17px;
}
.logo-link:hover {
  color: var(--text);
}

.logo-img {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  object-fit: contain;
}

.nav {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-link {
  font-size: 14px;
  font-weight: 500;
  color: var(--text-secondary);
  padding: 6px 0;
  position: relative;
  transition: color var(--transition);
}
.nav-link:hover,
.nav-link.active {
  color: var(--primary);
}
.nav-link::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--primary);
  border-radius: 1px;
  transition: width var(--transition);
}
.nav-link:hover::after,
.nav-link.active::after {
  width: 100%;
}

.nav-cta {
  background: var(--primary);
  color: #fff !important;
  padding: 7px 18px;
  border-radius: var(--radius-sm);
  font-weight: 600;
}
.nav-cta:hover {
  background: var(--primary-dark) !important;
  color: #fff !important;
}
.nav-cta::after {
  display: none;
}

.menu-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 24px;
  color: var(--text);
  cursor: pointer;
  padding: 4px;
}

/* Theme Toggle Button */
.theme-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  background: none;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  width: 36px;
  height: 36px;
  font-size: 18px;
  color: var(--text-secondary);
  cursor: pointer;
  transition: color var(--transition), border-color var(--transition), background var(--transition);
  flex-shrink: 0;
  margin-left: 12px;
}
.theme-toggle:hover {
  color: var(--primary);
  border-color: var(--primary);
}
.theme-toggle .ri-sun-line { display: none; }
.theme-toggle .ri-moon-line { display: block; }
[data-theme="dark"] .theme-toggle .ri-sun-line { display: block; }
[data-theme="dark"] .theme-toggle .ri-moon-line { display: none; }

/* ============================================
   Hero Section
   ============================================ */
.hero {
  padding: 130px 0 80px;
  overflow: hidden;
}

.hero-inner {
  display: flex;
  align-items: center;
  gap: 56px;
}

.hero-content {
  flex: 1;
  min-width: 0;
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 13px;
  font-weight: 600;
  color: var(--primary);
  background: rgba(46,97,150,.08);
  padding: 5px 14px;
  border-radius: 999px;
  margin-bottom: 20px;
  letter-spacing: .02em;
}

.hero-content h1 {
  font-size: 48px;
  font-weight: 800;
  line-height: 1.15;
  letter-spacing: -.03em;
  color: var(--text);
  margin-bottom: 16px;
}

.hero-subtitle {
  font-size: 20px;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: 16px;
  line-height: 1.4;
}

.hero-desc {
  font-size: 15px;
  color: var(--text-secondary);
  line-height: 1.75;
  margin-bottom: 32px;
  max-width: 480px;
}

.hero-actions {
  display: flex;
  gap: 14px;
  flex-wrap: wrap;
}

.hero-visual {
  flex-shrink: 0;
  width: 300px;
}

/* Phone mockup frame */
.phone-mockup {
  position: relative;
  width: 280px;
  margin: 0 auto;
  padding: 12px 10px;
  background: #1a2332;
  border-radius: 42px;
  box-shadow:
    0 30px 70px rgba(46,97,150,.22),
    0 12px 36px rgba(0,0,0,.14),
    inset 0 1px 1px rgba(255,255,255,.06);
}

.phone-notch {
  position: absolute;
  top: 8px;
  left: 50%;
  transform: translateX(-50%);
  width: 100px;
  height: 24px;
  background: #1a2332;
  border-radius: 0 0 18px 18px;
  z-index: 3;
}

.phone-mockup .hero-mockup {
  width: 100%;
  height: auto;
  border-radius: 32px;
  display: block;
}

/* ============================================
   Buttons
   ============================================ */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font);
  font-size: 15px;
  font-weight: 600;
  padding: 11px 26px;
  border-radius: var(--radius-md);
  border: 2px solid transparent;
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
  line-height: 1.4;
}

.btn-primary {
  background: var(--primary);
  color: #fff;
  border-color: var(--primary);
}
.btn-primary:hover {
  background: var(--primary-dark);
  border-color: var(--primary-dark);
  color: #fff;
  transform: translateY(-1px);
  box-shadow: 0 4px 14px rgba(46,97,150,.30);
}

.btn-outline {
  background: transparent;
  color: var(--primary);
  border-color: var(--border);
}
.btn-outline:hover {
  border-color: var(--primary);
  background: rgba(46,97,150,.04);
  color: var(--primary-dark);
  transform: translateY(-1px);
}

.btn-lg { padding: 13px 30px; font-size: 16px; }
.btn-xl { padding: 16px 40px; font-size: 17px; }

/* ============================================
   Showcase / Screenshots
   ============================================ */
.showcase {
  background: var(--bg-white);
}

.showcase-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}

.showcase-item {
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--bg-white);
  box-shadow: var(--card-shadow);
  transition: transform var(--transition), box-shadow var(--transition);
}
.showcase-item:hover {
  transform: translateY(-4px);
  box-shadow: var(--card-hover-shadow);
}
.showcase-item img {
  width: 100%;
  height: auto;
  display: block;
}
.showcase-item figcaption {
  padding: 16px 16px 18px;
  background: var(--bg-white);
}
.showcase-item figcaption h3 {
  font-size: 15px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 6px;
  letter-spacing: -.01em;
}
.showcase-item figcaption p {
  font-size: 13px;
  line-height: 1.65;
  color: var(--text-secondary);
}

/* ============================================
   Features Grid
   ============================================ */
.features {
  /* inherits bg from body */
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 22px;
}

.feature-card {
  background: var(--bg-white);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 30px 26px;
  transition: transform var(--transition), box-shadow var(--transition), border-color var(--transition);
}
.feature-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--card-hover-shadow);
  border-color: rgba(46,97,150,.25);
}

.feature-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  background: rgba(46,97,150,.08);
  color: var(--primary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  margin-bottom: 18px;
}

.feature-card h3 {
  font-size: 17px;
  font-weight: 700;
  margin-bottom: 10px;
  color: var(--text);
  letter-spacing: -.01em;
}

.feature-card p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.7;
}

/* ============================================
   Steps
   ============================================ */
.steps {
  background: var(--bg-white);
}

.step-list {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  counter-reset: step;
}

.step-item {
  position: relative;
  text-align: center;
  padding: 32px 20px;
  border-radius: var(--radius-lg);
  background: var(--bg);
  border: 1px solid var(--border);
  transition: transform var(--transition), box-shadow var(--transition);
}
.step-item:hover {
  transform: translateY(-3px);
  box-shadow: var(--card-hover-shadow);
}

.step-num {
  font-size: 36px;
  font-weight: 800;
  color: rgba(46,97,150,.15);
  margin-bottom: 14px;
  letter-spacing: -.02em;
}

.step-content h3 {
  font-size: 16px;
  font-weight: 700;
  color: var(--text);
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
}
.step-content h3 i {
  color: var(--primary);
  font-size: 18px;
}

.step-content p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.65;
}

/* ============================================
   FAQ
   ============================================ */
.faq-list {
  max-width: 720px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.faq-item {
  background: var(--bg-white);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: border-color var(--transition);
}
.faq-item[open] {
  border-color: rgba(46,97,150,.25);
}

.faq-item summary {
  padding: 18px 22px;
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  user-select: none;
  transition: color var(--transition);
}
.faq-item summary::-webkit-details-marker {
  display: none;
}
.faq-item summary::after {
  content: '\EA14';
  font-family: 'remixicon';
  font-size: 18px;
  color: var(--text-muted);
  transition: transform var(--transition);
  flex-shrink: 0;
}
.faq-item[open] summary::after {
  content: '\EA0D';
  transform: rotate(180deg);
}
.faq-item summary:hover {
  color: var(--primary);
}

.faq-answer {
  padding: 0 22px 18px;
}
.faq-answer p {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.75;
}

/* ============================================
   Reviews
   ============================================ */
.reviews {
  background: var(--bg-white);
}

.review-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 18px;
}

.review-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  padding: 22px 20px;
  transition: transform var(--transition), box-shadow var(--transition);
}
.review-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--card-hover-shadow);
}

.review-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 12px;
  gap: 10px;
}

.review-tag {
  font-size: 12px;
  font-weight: 600;
  color: var(--primary);
  background: rgba(46,97,150,.08);
  padding: 3px 10px;
  border-radius: 999px;
  white-space: nowrap;
}

.time {
  font-size: 12px;
  color: var(--text-muted);
  font-family: var(--font-mono);
  white-space: nowrap;
}

.review-text {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.75;
}

/* ============================================
   Download Section
   ============================================ */
.download {
  /* inherits bg */
}

.download-box {
  max-width: 520px;
  margin: 0 auto;
  background: var(--bg-white);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 44px 36px;
  text-align: center;
  box-shadow: 0 4px 20px rgba(46,97,150,.08);
}

.download-info {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px 28px;
  margin-bottom: 28px;
  text-align: left;
}

.info-row {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.info-label {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: .05em;
}

.info-value {
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
}

.download-btn {
  width: 100%;
  justify-content: center;
  font-size: 17px;
  padding: 16px 40px;
  margin-bottom: 14px;
}

.download-note {
  font-size: 13px;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 5px;
}
.download-note i {
  font-size: 15px;
  position: relative;
  top: -1px;
}

/* ============================================
   Footer
   ============================================ */
.footer {
  background: var(--footer-bg);
  color: rgba(255,255,255,.65);
  padding: 48px 0 36px;
}

.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 20px;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 14px;
  font-weight: 500;
  color: rgba(255,255,255,.85);
}

.footer-logo {
  width: 28px;
  height: 28px;
  border-radius: 6px;
  object-fit: contain;
}

.footer-links {
  display: flex;
  gap: 24px;
  flex-wrap: wrap;
  justify-content: center;
}
.footer-links a {
  color: rgba(255,255,255,.55);
  font-size: 14px;
  transition: color var(--transition);
}
.footer-links a:hover {
  color: #fff;
}

.footer-copy {
  font-size: 13px;
  color: rgba(255,255,255,.35);
}

/* ============================================
   Responsive Design
   ============================================ */

/* Tablet & below */
@media (max-width: 960px) {
  :root {
    --section-py: 60px;
  }

  .hero-inner {
    flex-direction: column;
    text-align: center;
  }
  .hero-desc {
    margin-left: auto;
    margin-right: auto;
  }
  .hero-actions {
    justify-content: center;
  }
  .hero-visual {
    width: 240px;
  }
  .phone-mockup {
    width: 220px;
    padding: 10px 8px;
    border-radius: 36px;
  }
  .phone-notch {
    width: 80px;
    height: 20px;
    top: 6px;
  }

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

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

  .step-list {
    grid-template-columns: repeat(2, 1fr);
  }

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

/* Mobile */
@media (max-width: 640px) {
  :root {
    --section-py: 48px;
  }

  .nav {
    display: none;
    position: fixed;
    top: 64px;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--nav-mobile-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 24px;
    z-index: 999;
  }
  .nav.open {
    display: flex;
  }
  .nav-link {
    font-size: 18px;
  }
  .nav-cta {
    font-size: 16px;
    padding: 10px 28px;
  }

  .menu-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
  }
  .menu-toggle.open i::before {
    content: '\EB69'; /* close icon */
  }

  .hero {
    padding: 110px 0 56px;
  }
  .hero-content h1 {
    font-size: 34px;
  }
  .hero-subtitle {
    font-size: 17px;
  }
  .hero-visual {
    width: 200px;
  }
  .phone-mockup {
    width: 186px;
    padding: 8px 6px;
    border-radius: 32px;
  }
  .phone-notch {
    width: 68px;
    height: 18px;
    top: 5px;
  }

  .section-title {
    font-size: 26px;
  }

  .showcase-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
  }

  .feature-grid {
    grid-template-columns: 1fr;
  }

  .step-list {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .review-grid {
    grid-template-columns: 1fr;
  }

  .download-info {
    grid-template-columns: 1fr;
    gap: 12px;
  }

  .download-box {
    padding: 32px 24px;
  }
}

/* Small mobile */
@media (max-width: 380px) {
  .hero-content h1 {
    font-size: 28px;
  }
  .hero-visual {
    width: 176px;
  }
  .phone-mockup {
    width: 164px;
    padding: 7px 5px;
    border-radius: 28px;
  }
  .phone-notch {
    width: 60px;
    height: 16px;
    top: 4px;
  }
  .btn-lg {
    padding: 11px 24px;
    font-size: 15px;
  }
}

/* ============================================
   Dark Mode Adjustments
   ============================================ */
[data-theme="dark"] .btn-secondary {
  background: var(--bg-white);
  color: var(--text);
  border-color: var(--border);
}
[data-theme="dark"] .btn-secondary:hover {
  background: var(--border);
}
[data-theme="dark"] .review-card {
  background: var(--bg-white);
}
[data-theme="dark"] .faq-item {
  background: var(--bg-white);
}
[data-theme="dark"] .faq-item summary {
  color: var(--text);
}
[data-theme="dark"] .faq-answer p {
  color: var(--text-secondary);
}
[data-theme="dark"] .footer-links a {
  color: rgba(255,255,255,.45);
}
[data-theme="dark"] .footer-links a:hover {
  color: rgba(255,255,255,.85);
}
[data-theme="dark"] .footer-contact {
  color: rgba(255,255,255,.35);
}

/* Theme transition */
body, .header, .footer, .feature-card, .review-card, .faq-item,
.download-box, .step-item, .showcase-item figcaption {
  transition: background-color .3s ease, border-color .3s ease, color .3s ease;
}