/* ========================================
   MuMu模拟器官网 - 浅蓝 × 深蓝主题
   ======================================== */

:root {
  --blue-50: #e3f2fd;
  --blue-100: #bbdefb;
  --blue-200: #90caf9;
  --blue-300: #64b5f6;
  --blue-400: #42a5f5;
  --blue-500: #2196f3;
  --blue-600: #1e88e5;
  --blue-700: #1565c0;
  --blue-800: #0d47a1;
  --blue-900: #0a2f6e;
  --blue-950: #061a3d;

  --gradient-hero: linear-gradient(135deg, #e3f2fd 0%, #bbdefb 40%, #1565c0 100%);
  --gradient-primary: linear-gradient(135deg, #2196f3 0%, #0d47a1 100%);
  --gradient-text: linear-gradient(90deg, #1565c0, #42a5f5);

  --text-primary: #0a2f6e;
  --text-secondary: #455a64;
  --text-muted: #78909c;
  --text-inverse: #ffffff;

  --bg-page: #f5f9ff;
  --bg-card: #ffffff;
  --bg-dark: #0d47a1;

  --shadow-sm: 0 2px 8px rgba(13, 71, 161, 0.08);
  --shadow-md: 0 8px 24px rgba(13, 71, 161, 0.12);
  --shadow-lg: 0 16px 48px rgba(13, 71, 161, 0.18);

  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 20px;
  --radius-full: 9999px;

  --header-height: 72px;
  --container-max: 1200px;
  --transition: 0.25s ease;
}

*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--text-primary);
  background: var(--bg-page);
  min-height: 100vh;
}

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

a {
  color: var(--blue-700);
  text-decoration: none;
  transition: color var(--transition);
}

a:hover {
  color: var(--blue-500);
}

ul, ol {
  list-style: none;
}

.container {
  width: 100%;
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 24px;
}

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

.skip-link {
  position: absolute;
  top: -100%;
  left: 16px;
  z-index: 9999;
  padding: 8px 16px;
  background: var(--blue-800);
  color: white;
  border-radius: var(--radius-sm);
}

.skip-link:focus {
  top: 16px;
}

/* ========== Buttons ========== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 28px;
  font-size: 15px;
  font-weight: 600;
  border-radius: var(--radius-full);
  border: 2px solid transparent;
  cursor: pointer;
  transition: all var(--transition);
  white-space: nowrap;
}

.btn-primary {
  background: var(--gradient-primary);
  color: var(--text-inverse);
  box-shadow: 0 4px 16px rgba(33, 150, 243, 0.35);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(33, 150, 243, 0.45);
  color: var(--text-inverse);
}

.btn-outline {
  background: transparent;
  color: var(--blue-700);
  border-color: var(--blue-300);
}

.btn-outline:hover {
  background: var(--blue-50);
  border-color: var(--blue-500);
  color: var(--blue-800);
}

.btn-white {
  background: white;
  color: var(--blue-800);
  box-shadow: var(--shadow-md);
}

.btn-white:hover {
  transform: translateY(-2px);
  color: var(--blue-700);
}

.btn-sm {
  padding: 8px 20px;
  font-size: 14px;
}

.btn-lg {
  padding: 16px 36px;
  font-size: 16px;
}

.btn-block {
  width: 100%;
}

/* ========== Header ========== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-height);
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid rgba(13, 71, 161, 0.08);
}

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

.logo {
  display: flex;
  align-items: center;
  gap: 10px;
  font-size: 20px;
  font-weight: 600;
  color: var(--blue-800);
}

.logo strong {
  color: var(--blue-500);
  font-weight: 800;
}

.main-nav ul {
  display: flex;
  gap: 32px;
}

.main-nav a {
  font-size: 15px;
  font-weight: 500;
  color: var(--text-secondary);
  position: relative;
}

.main-nav a:hover,
.main-nav a[aria-current="page"] {
  color: var(--blue-700);
}

.main-nav a[aria-current="page"]::after {
  content: "";
  position: absolute;
  bottom: -4px;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--blue-500);
  border-radius: 1px;
}

/* ========== Hero ========== */
.hero {
  position: relative;
  overflow: hidden;
  padding: 80px 0 100px;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background: var(--gradient-hero);
  z-index: 0;
}

.hero-bg::before {
  content: "";
  position: absolute;
  top: -50%;
  right: -20%;
  width: 80%;
  height: 150%;
  background: radial-gradient(ellipse, rgba(33, 150, 243, 0.15) 0%, transparent 70%);
}

.hero-bg::after {
  content: "";
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 120px;
  background: linear-gradient(to top, var(--bg-page), transparent);
}

.hero-inner {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}

.hero-badge {
  display: inline-block;
  padding: 6px 16px;
  background: rgba(255, 255, 255, 0.7);
  border: 1px solid var(--blue-200);
  border-radius: var(--radius-full);
  font-size: 13px;
  font-weight: 600;
  color: var(--blue-700);
  margin-bottom: 20px;
}

.hero h1 {
  font-size: clamp(2rem, 5vw, 3.2rem);
  font-weight: 800;
  line-height: 1.2;
  color: var(--blue-900);
  margin-bottom: 20px;
}

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

.hero-desc {
  font-size: 18px;
  color: var(--text-secondary);
  margin-bottom: 32px;
  max-width: 520px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin-bottom: 20px;
}

.hero-meta {
  font-size: 13px;
  color: var(--text-muted);
}

/* Mock window */
.hero-visual {
  display: flex;
  justify-content: center;
}

.mock-window {
  width: 100%;
  max-width: 420px;
  background: var(--blue-950);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  transform: perspective(800px) rotateY(-5deg) rotateX(2deg);
}

.mock-titlebar {
  display: flex;
  gap: 8px;
  padding: 12px 16px;
  background: rgba(255, 255, 255, 0.05);
}

.mock-titlebar span {
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.2);
}

.mock-titlebar span:first-child { background: #ff5f57; }
.mock-titlebar span:nth-child(2) { background: #febc2e; }
.mock-titlebar span:nth-child(3) { background: #28c840; }

.mock-screen {
  aspect-ratio: 16/10;
  background: linear-gradient(160deg, #1a237e 0%, #0d47a1 50%, #1565c0 100%);
  position: relative;
}

.mock-game-ui {
  position: absolute;
  inset: 0;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 16px;
}

.mock-fps {
  align-self: flex-end;
  padding: 4px 12px;
  background: rgba(0, 0, 0, 0.5);
  color: #4caf50;
  font-size: 14px;
  font-weight: 700;
  border-radius: var(--radius-sm);
  font-family: monospace;
}

.mock-hud {
  height: 60%;
  background: linear-gradient(to top, rgba(0,0,0,0.3), transparent);
  border-radius: var(--radius-sm);
}

/* ========== Sections ========== */
.section-header {
  text-align: center;
  margin-bottom: 48px;
}

.section-header h2 {
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  font-weight: 800;
  color: var(--blue-900);
  margin-bottom: 12px;
}

.section-header p {
  font-size: 17px;
  color: var(--text-secondary);
}

.section-cta {
  text-align: center;
  margin-top: 40px;
}

.section-cta a {
  font-weight: 600;
  font-size: 16px;
}

.features-preview {
  padding: 100px 0;
}

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

.feature-card {
  background: var(--bg-card);
  padding: 32px 24px;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  border: 1px solid rgba(13, 71, 161, 0.06);
  transition: all var(--transition);
}

.feature-card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: var(--blue-200);
}

.feature-icon {
  font-size: 36px;
  margin-bottom: 16px;
}

.feature-card h3 {
  font-size: 18px;
  font-weight: 700;
  color: var(--blue-800);
  margin-bottom: 10px;
}

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

/* Games */
.games-section {
  padding: 80px 0;
  background: linear-gradient(180deg, var(--blue-50) 0%, var(--bg-page) 100%);
}

.game-tags {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
}

.game-tags li {
  padding: 10px 24px;
  background: white;
  border: 1px solid var(--blue-200);
  border-radius: var(--radius-full);
  font-size: 15px;
  font-weight: 500;
  color: var(--blue-700);
  transition: all var(--transition);
}

.game-tags li:hover {
  background: var(--blue-700);
  color: white;
  border-color: var(--blue-700);
}

/* Download CTA */
.download-cta {
  padding: 80px 0;
}

.download-cta-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
  padding: 48px 56px;
  background: var(--gradient-primary);
  border-radius: var(--radius-lg);
  color: white;
}

.download-cta h2 {
  font-size: 1.8rem;
  font-weight: 800;
  margin-bottom: 8px;
}

.download-cta p {
  opacity: 0.9;
  font-size: 16px;
}

/* FAQ */
.faq-preview {
  padding: 80px 0 100px;
}

.faq-list {
  max-width: 800px;
  margin: 0 auto;
}

.faq-item {
  background: white;
  border: 1px solid rgba(13, 71, 161, 0.08);
  border-radius: var(--radius-md);
  margin-bottom: 12px;
  overflow: hidden;
}

.faq-item summary {
  padding: 20px 24px;
  font-weight: 600;
  font-size: 16px;
  color: var(--blue-800);
  cursor: pointer;
  list-style: none;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.faq-item summary::-webkit-details-marker { display: none; }

.faq-item summary::after {
  content: "+";
  font-size: 20px;
  color: var(--blue-500);
  transition: transform var(--transition);
}

.faq-item[open] summary::after {
  transform: rotate(45deg);
}

.faq-item p {
  padding: 0 24px 20px;
  color: var(--text-secondary);
  font-size: 15px;
  line-height: 1.7;
}

/* ========== Inner Pages ========== */
.page-hero {
  padding: 48px 0 32px;
  background: linear-gradient(180deg, var(--blue-50) 0%, var(--bg-page) 100%);
}

.breadcrumb {
  display: flex;
  gap: 8px;
  font-size: 14px;
  color: var(--text-muted);
  margin-bottom: 16px;
}

.breadcrumb li:not(:last-child)::after {
  content: "›";
  margin-left: 8px;
  color: var(--blue-300);
}

.page-hero h1 {
  font-size: clamp(1.8rem, 4vw, 2.6rem);
  font-weight: 800;
  color: var(--blue-900);
  margin-bottom: 8px;
}

.page-desc {
  font-size: 17px;
  color: var(--text-secondary);
}

/* Download page */
.download-section {
  padding: 48px 0 80px;
}

.download-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
}

.download-card {
  background: white;
  padding: 40px;
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-md);
  border: 1px solid rgba(13, 71, 161, 0.08);
}

.download-card-header {
  display: flex;
  align-items: center;
  gap: 20px;
  margin-bottom: 24px;
}

.download-card h2 {
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--blue-800);
}

.download-card-header p {
  font-size: 14px;
  color: var(--text-muted);
}

.download-specs {
  margin-bottom: 28px;
}

.download-specs li {
  padding: 8px 0;
  font-size: 15px;
  color: var(--text-secondary);
  border-bottom: 1px solid var(--blue-50);
}

.download-note {
  margin-top: 12px;
  font-size: 12px;
  color: var(--text-muted);
  font-family: monospace;
  word-break: break-all;
}

.install-guide {
  padding: 60px 0;
  background: var(--blue-50);
}

.install-guide h2,
.requirements h2 {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--blue-900);
  margin-bottom: 32px;
  text-align: center;
}

.steps-list {
  max-width: 700px;
  margin: 0 auto;
  counter-reset: step;
}

.steps-list li {
  counter-increment: step;
  position: relative;
  padding: 24px 24px 24px 72px;
  background: white;
  border-radius: var(--radius-md);
  margin-bottom: 16px;
  box-shadow: var(--shadow-sm);
}

.steps-list li::before {
  content: counter(step);
  position: absolute;
  left: 24px;
  top: 24px;
  width: 36px;
  height: 36px;
  background: var(--gradient-primary);
  color: white;
  font-weight: 700;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
}

.steps-list h3 {
  font-size: 17px;
  font-weight: 700;
  color: var(--blue-800);
  margin-bottom: 6px;
}

.steps-list p {
  font-size: 15px;
  color: var(--text-secondary);
}

.requirements {
  padding: 60px 0 80px;
}

.req-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 32px;
}

.req-grid h3 {
  font-size: 18px;
  font-weight: 700;
  color: var(--blue-700);
  margin-bottom: 16px;
  padding-bottom: 8px;
  border-bottom: 2px solid var(--blue-200);
}

.req-grid ul li {
  padding: 6px 0;
  font-size: 15px;
  color: var(--text-secondary);
}

.req-grid ul li::before {
  content: "✓ ";
  color: var(--blue-500);
  font-weight: 700;
}

/* Features detail */
.features-detail {
  padding: 48px 0 80px;
}

.feature-detail-card {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
  padding: 48px 0;
}

.feature-detail-card.reverse {
  direction: rtl;
}

.feature-detail-card.reverse > * {
  direction: ltr;
}

.feature-detail-content h2 {
  font-size: 1.6rem;
  font-weight: 800;
  color: var(--blue-900);
  margin-bottom: 16px;
}

.feature-detail-content p {
  font-size: 16px;
  color: var(--text-secondary);
  margin-bottom: 16px;
  line-height: 1.8;
}

.feature-detail-content ul li {
  padding: 6px 0;
  font-size: 15px;
  color: var(--text-secondary);
}

.feature-detail-content ul li::before {
  content: "▸ ";
  color: var(--blue-500);
}

.feature-detail-visual {
  height: 280px;
  border-radius: var(--radius-lg);
  background: var(--gradient-primary);
  position: relative;
  overflow: hidden;
}

.perf-visual .fps-badge {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  font-size: 48px;
  font-weight: 900;
  color: rgba(255, 255, 255, 0.9);
  font-family: monospace;
}

.multi-visual {
  background: linear-gradient(135deg, #1565c0, #0d47a1);
}

.multi-visual::before,
.multi-visual::after {
  content: "";
  position: absolute;
  width: 60%;
  height: 50%;
  background: rgba(255, 255, 255, 0.1);
  border-radius: var(--radius-sm);
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.multi-visual::before { top: 15%; left: 10%; }
.multi-visual::after { bottom: 15%; right: 10%; }

.keymap-visual {
  background: linear-gradient(135deg, #1e88e5, #0a2f6e);
}

.vt-visual {
  background: linear-gradient(135deg, #42a5f5, #1565c0);
}

.faq-full {
  padding: 48px 0 100px;
}

.faq-list-full {
  max-width: 860px;
}

/* ========== Footer ========== */
.site-footer {
  background: var(--blue-950);
  color: rgba(255, 255, 255, 0.7);
  padding: 48px 0 32px;
}

.footer-inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 24px;
  text-align: center;
}

.footer-brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.footer-brand p {
  font-size: 14px;
}

.footer-nav ul {
  display: flex;
  gap: 24px;
}

.footer-nav a {
  color: rgba(255, 255, 255, 0.7);
  font-size: 14px;
}

.footer-nav a:hover {
  color: white;
}

.footer-copy {
  font-size: 13px;
  opacity: 0.5;
}

/* ========== Responsive ========== */
@media (max-width: 1024px) {
  .feature-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .hero-inner {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .hero-desc {
    margin-left: auto;
    margin-right: auto;
  }

  .hero-actions {
    justify-content: center;
  }

  .hero-visual {
    order: -1;
  }

  .mock-window {
    max-width: 320px;
    transform: none;
  }
}

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

  .feature-grid,
  .download-grid,
  .req-grid,
  .feature-detail-card {
    grid-template-columns: 1fr;
  }

  .feature-detail-card.reverse {
    direction: ltr;
  }

  .download-cta-inner {
    flex-direction: column;
    text-align: center;
    padding: 36px 28px;
  }

  .hero {
    padding: 48px 0 64px;
  }

  .features-preview,
  .games-section,
  .download-cta,
  .faq-preview {
    padding: 60px 0;
  }
}