/* ===== CSS Custom Properties ===== */
:root,
[data-theme="dark"] {
  /* Color System */
  --color-bg-primary: #0a0e14;
  --color-bg-secondary: #111720;
  --color-bg-tertiary: #161c26;
  --color-bg-card: #141a24;
  --color-bg-card-hover: #1a2230;
  --color-bg-elevated: #1c2432;

  --color-border: #1e2a3a;
  --color-border-light: #263548;
  --color-border-accent: #2a4a6b;

  --color-text-primary: #e8ecf1;
  --color-text-secondary: #8899aa;
  --color-text-tertiary: #5a6d80;
  --color-text-muted: #3d4f60;

  --color-accent: #d4a853;
  --color-accent-light: #e8c97a;
  --color-accent-dark: #b8922e;
  --color-accent-glow: rgba(212, 168, 83, 0.15);

  --color-blue: #4a9eff;
  --color-blue-light: #7ab8ff;
  --color-blue-glow: rgba(74, 158, 255, 0.12);

  --color-green: #34d399;
  --color-green-glow: rgba(52, 211, 153, 0.12);

  --color-red: #f87171;
  --color-red-glow: rgba(248, 113, 113, 0.12);

  --color-gradient-hero: linear-gradient(135deg, #0a0e14 0%, #111720 40%, #0f1825 100%);
  --color-gradient-card: linear-gradient(145deg, #161c26 0%, #141a24 100%);
  --color-gradient-accent: linear-gradient(135deg, #d4a853 0%, #e8c97a 50%, #b8922e 100%);

  /* Typography */
  --font-display: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-body: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Consolas', monospace;

  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;
  --text-4xl: 2.25rem;
  --text-5xl: 3rem;
  --text-6xl: 3.75rem;

  --leading-tight: 1.2;
  --leading-normal: 1.6;
  --leading-relaxed: 1.8;

  --weight-normal: 400;
  --weight-medium: 500;
  --weight-semibold: 600;
  --weight-bold: 700;
  --weight-extrabold: 800;

  /* Spacing */
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
  --space-32: 8rem;

  /* Layout */
  --max-width: 1280px;
  --max-width-narrow: 860px;
  --nav-height: 72px;

  /* Effects */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.25rem;

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 40px var(--color-accent-glow);
  --shadow-glow-blue: 0 0 40px var(--color-blue-glow);

  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 400ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* ===== Light Theme ===== */
[data-theme="light"] {
  --color-bg-primary: #f8f9fb;
  --color-bg-secondary: #eef1f5;
  --color-bg-tertiary: #e2e6ed;
  --color-bg-card: #ffffff;
  --color-bg-card-hover: #f5f7fa;
  --color-bg-elevated: #ffffff;

  --color-border: #dce1e8;
  --color-border-light: #c8ced8;
  --color-border-accent: #8b9eb5;

  --color-text-primary: #1a1d24;
  --color-text-secondary: #4a5568;
  --color-text-tertiary: #718096;
  --color-text-muted: #a0aec0;

  --color-gradient-hero: linear-gradient(135deg, #f0f4f8 0%, #ffffff 40%, #f8f9fb 100%);
  --color-gradient-card: linear-gradient(145deg, #ffffff 0%, #fafbfc 100%);

  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.1);
  --shadow-glow: 0 0 30px rgba(180, 140, 60, 0.2);
  --shadow-glow-blue: 0 0 30px rgba(74, 158, 255, 0.15);
}

/* Theme toggle */
.theme-toggle {
  background: none;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  font-size: 1.2rem;
  transition: all var(--transition-fast);
  color: var(--color-text-primary);
  margin-left: var(--space-2);
}

.theme-toggle:hover {
  border-color: var(--color-accent);
  background: var(--color-bg-tertiary);
}

/* ===== Payment Modal ===== */
.pay-overlay {
  position: fixed;
  top: 0; left: 0; right: 0; bottom: 0;
  background: rgba(0, 0, 0, 0.7);
  backdrop-filter: blur(4px);
  z-index: 200;
  display: none;
  align-items: center;
  justify-content: center;
  padding: var(--space-4);
}

.pay-overlay.open {
  display: flex;
  animation: fadeIn 0.2s ease;
}

.pay-modal {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-2xl);
  max-width: 480px;
  width: 100%;
  max-height: 90vh;
  overflow-y: auto;
  box-shadow: var(--shadow-lg);
}

.pay-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-6);
  border-bottom: 1px solid var(--color-border);
}

.pay-header h3 {
  font-size: var(--text-lg);
  font-weight: var(--weight-bold);
}

.pay-close {
  background: none;
  border: none;
  font-size: 1.5rem;
  cursor: pointer;
  color: var(--color-text-tertiary);
  line-height: 1;
  padding: 0;
}

.pay-close:hover {
  color: var(--color-text-primary);
}

.pay-amount {
  text-align: center;
  padding: var(--space-6);
  border-bottom: 1px solid var(--color-border);
}

.pay-amount .label {
  font-size: var(--text-sm);
  color: var(--color-text-tertiary);
  margin-bottom: var(--space-2);
}

.pay-amount .value {
  font-family: var(--font-display);
  font-size: var(--text-4xl);
  font-weight: var(--weight-extrabold);
  color: var(--color-accent);
}

.pay-methods {
  padding: var(--space-6);
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-3);
}

.pay-method-btn {
  padding: var(--space-4) var(--space-2);
  background: var(--color-bg-tertiary);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-lg);
  cursor: pointer;
  text-align: center;
  transition: all var(--transition-fast);
  color: var(--color-text-secondary);
}

.pay-method-btn:hover,
.pay-method-btn.active {
  border-color: var(--color-accent);
  background: var(--color-accent-glow);
  color: var(--color-text-primary);
}

.pay-method-btn .icon {
  font-size: 1.8rem;
  display: block;
  margin-bottom: var(--space-2);
}

.pay-method-btn .name {
  font-size: var(--text-xs);
  font-weight: var(--weight-semibold);
}

.pay-content {
  padding: var(--space-6);
  text-align: center;
  display: none;
}

.pay-content.active {
  display: block;
  animation: fadeIn 0.3s ease;
}

.pay-qr {
  width: 200px;
  height: 200px;
  border-radius: var(--radius-lg);
  border: 2px solid var(--color-border);
  margin: 0 auto var(--space-4);
  display: block;
  object-fit: cover;
}

.pay-hint {
  font-size: var(--text-sm);
  color: var(--color-text-tertiary);
  margin-top: var(--space-3);
}

.pay-usdt-box {
  background: var(--color-bg-tertiary);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  margin: var(--space-4) 0;
  text-align: left;
}

.pay-usdt-box .row {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-2) 0;
  font-size: var(--text-sm);
}

.pay-usdt-box .row:not(:last-child) {
  border-bottom: 1px solid var(--color-border);
}

.pay-usdt-box .row .key {
  color: var(--color-text-tertiary);
}

.pay-usdt-box .row .val {
  color: var(--color-text-primary);
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  word-break: break-all;
  text-align: right;
  max-width: 280px;
}

.pay-copy-btn {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-sm);
  padding: 2px 8px;
  font-size: var(--text-xs);
  cursor: pointer;
  color: var(--color-text-secondary);
  margin-left: var(--space-2);
}

.pay-copy-btn:hover {
  border-color: var(--color-accent);
  color: var(--color-accent);
}

.pay-footer {
  padding: var(--space-4) var(--space-6);
  border-top: 1px solid var(--color-border);
  text-align: center;
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}

.pay-footer a {
  font-size: var(--text-xs);
}

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

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

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

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--color-accent-light);
}

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

::selection {
  background: var(--color-accent-dark);
  color: #fff;
}

/* ===== Typography Utility ===== */
.text-gradient {
  background: var(--color-gradient-accent);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.text-gradient-blue {
  background: linear-gradient(135deg, var(--color-blue) 0%, var(--color-blue-light) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* ===== Navigation ===== */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  height: var(--nav-height);
  background: rgba(10, 14, 20, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--color-border);
  transition: background var(--transition-base);
}

.nav.scrolled {
  background: rgba(10, 14, 20, 0.95);
  box-shadow: var(--shadow-md);
}

.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-8);
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: var(--weight-bold);
  color: var(--color-text-primary);
  letter-spacing: -0.02em;
}

.nav-brand-icon {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  background: var(--color-gradient-accent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.25rem;
  color: #1a1a1a;
  font-weight: var(--weight-extrabold);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  list-style: none;
}

.nav-links a {
  display: block;
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  color: var(--color-text-secondary);
  transition: all var(--transition-fast);
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--color-text-primary);
  background: var(--color-bg-tertiary);
}

.nav-cta {
  padding: var(--space-2) var(--space-5) !important;
  border-radius: var(--radius-lg) !important;
  background: var(--color-gradient-accent) !important;
  color: #1a1a1a !important;
  font-weight: var(--weight-semibold) !important;
}

.nav-cta:hover {
  transform: translateY(-1px);
  box-shadow: var(--shadow-glow);
  color: #1a1a1a !important;
}

.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: var(--space-2);
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--color-text-primary);
  margin: 5px 0;
  border-radius: 2px;
  transition: all var(--transition-fast);
}

/* ===== Page Header ===== */
.page-header {
  padding: calc(var(--nav-height) + var(--space-20)) var(--space-8) var(--space-16);
  text-align: center;
  background: var(--color-gradient-hero);
  border-bottom: 1px solid var(--color-border);
  position: relative;
  overflow: hidden;
}

.page-header::before {
  content: '';
  position: absolute;
  top: -50%;
  left: 50%;
  transform: translateX(-50%);
  width: 800px;
  height: 800px;
  background: radial-gradient(circle, var(--color-accent-glow) 0%, transparent 70%);
  pointer-events: none;
}

.page-header-label {
  display: inline-block;
  padding: var(--space-1) var(--space-4);
  border-radius: 999px;
  background: var(--color-accent-glow);
  border: 1px solid var(--color-accent-dark);
  color: var(--color-accent-light);
  font-size: var(--text-sm);
  font-weight: var(--weight-medium);
  margin-bottom: var(--space-6);
  position: relative;
}

.page-header h1 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, var(--text-5xl));
  font-weight: var(--weight-extrabold);
  line-height: var(--leading-tight);
  margin-bottom: var(--space-6);
  letter-spacing: -0.03em;
  position: relative;
}

.page-header p {
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  max-width: 600px;
  margin: 0 auto;
  position: relative;
  line-height: var(--leading-relaxed);
}

/* ===== Buttons ===== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  border-radius: var(--radius-lg);
  font-family: var(--font-body);
  font-size: var(--text-sm);
  font-weight: var(--weight-semibold);
  border: none;
  cursor: pointer;
  transition: all var(--transition-base);
  text-decoration: none;
  line-height: 1;
  white-space: nowrap;
}

.btn-primary {
  background: var(--color-gradient-accent);
  color: #1a1a1a;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-glow);
  color: #1a1a1a;
}

.btn-secondary {
  background: transparent;
  color: var(--color-text-primary);
  border: 1px solid var(--color-border-light);
}

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

.btn-lg {
  padding: var(--space-4) var(--space-8);
  font-size: var(--text-base);
  border-radius: var(--radius-xl);
}

.btn-xl {
  padding: var(--space-5) var(--space-10);
  font-size: var(--text-lg);
  border-radius: var(--radius-2xl);
}

.btn-block {
  width: 100%;
  justify-content: center;
}

/* ===== Section Common ===== */
.section {
  padding: var(--space-24) var(--space-8);
}

.section-label {
  display: inline-block;
  font-size: var(--text-xs);
  font-weight: var(--weight-bold);
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-accent);
  margin-bottom: var(--space-4);
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 3.5vw, var(--text-4xl));
  font-weight: var(--weight-bold);
  line-height: var(--leading-tight);
  margin-bottom: var(--space-6);
  letter-spacing: -0.02em;
}

.section-desc {
  font-size: var(--text-lg);
  color: var(--color-text-secondary);
  max-width: 640px;
  line-height: var(--leading-relaxed);
}

.section-header {
  text-align: center;
  margin-bottom: var(--space-16);
}

.section-header .section-desc {
  margin: 0 auto;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 var(--space-8);
}

.container-narrow {
  max-width: var(--max-width-narrow);
  margin: 0 auto;
  padding: 0 var(--space-8);
}

/* ===== Cards ===== */
.card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  padding: var(--space-8);
  transition: all var(--transition-base);
}

.card:hover {
  background: var(--color-bg-card-hover);
  border-color: var(--color-border-light);
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
}

.card-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 1.5rem;
  margin-bottom: var(--space-5);
}

.card-icon.gold {
  background: var(--color-accent-glow);
}

.card-icon.blue {
  background: var(--color-blue-glow);
}

.card-icon.green {
  background: var(--color-green-glow);
}

.card-icon.red {
  background: var(--color-red-glow);
}

.card h3 {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: var(--weight-semibold);
  margin-bottom: var(--space-3);
  line-height: var(--leading-tight);
}

.card p {
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
  line-height: var(--leading-relaxed);
}

/* ===== Grids ===== */
.grid-2 {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-6);
}

.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-6);
}

.grid-4 {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-6);
}

/* ===== Stats Bar ===== */
.stats-bar {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-6);
  padding: var(--space-12) 0;
  border-top: 1px solid var(--color-border);
  border-bottom: 1px solid var(--color-border);
  background: var(--color-bg-secondary);
}

.stat-item {
  text-align: center;
  padding: var(--space-4);
}

.stat-value {
  font-family: var(--font-display);
  font-size: var(--text-4xl);
  font-weight: var(--weight-extrabold);
  line-height: 1;
  margin-bottom: var(--space-2);
}

.stat-value .plus {
  color: var(--color-accent);
}

.stat-label {
  font-size: var(--text-sm);
  color: var(--color-text-tertiary);
  font-weight: var(--weight-medium);
}

/* ===== Footer ===== */
.footer {
  background: var(--color-bg-secondary);
  border-top: 1px solid var(--color-border);
  padding: var(--space-16) var(--space-8) var(--space-8);
}

.footer-grid {
  max-width: var(--max-width);
  margin: 0 auto 0;
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-12);
}

.footer-brand p {
  color: var(--color-text-tertiary);
  font-size: var(--text-sm);
  line-height: var(--leading-relaxed);
  margin-top: var(--space-4);
  max-width: 300px;
}

.footer-col h4 {
  font-size: var(--text-sm);
  font-weight: var(--weight-semibold);
  color: var(--color-text-primary);
  margin-bottom: var(--space-4);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.footer-col ul {
  list-style: none;
}

.footer-col ul li {
  margin-bottom: var(--space-3);
}

.footer-col ul li a {
  color: var(--color-text-tertiary);
  font-size: var(--text-sm);
  transition: color var(--transition-fast);
}

.footer-col ul li a:hover {
  color: var(--color-text-primary);
}

.footer-bottom {
  max-width: var(--max-width);
  margin: var(--space-12) auto 0;
  padding-top: var(--space-8);
  border-top: 1px solid var(--color-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}

.footer-contact {
  display: flex;
  gap: var(--space-4);
}

.footer-contact a {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-md);
  background: var(--color-bg-tertiary);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-secondary);
  transition: all var(--transition-fast);
}

.footer-contact a:hover {
  background: var(--color-bg-card-hover);
  color: var(--color-accent);
}

/* ===== Feature List ===== */
.feature-list {
  list-style: none;
}

.feature-list li {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  padding: var(--space-3) 0;
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
}

.feature-list li::before {
  content: '✓';
  color: var(--color-green);
  font-weight: var(--weight-bold);
  flex-shrink: 0;
  margin-top: 1px;
}

/* ===== Tag ===== */
.tag {
  display: inline-block;
  padding: var(--space-1) var(--space-3);
  border-radius: 999px;
  font-size: var(--text-xs);
  font-weight: var(--weight-medium);
}

.tag-green {
  background: var(--color-green-glow);
  color: var(--color-green);
}

.tag-blue {
  background: var(--color-blue-glow);
  color: var(--color-blue);
}

.tag-gold {
  background: var(--color-accent-glow);
  color: var(--color-accent-light);
}

/* ===== Divider ===== */
.divider {
  border: none;
  border-top: 1px solid var(--color-border);
}

/* ===== Mobile Menu ===== */
/* ===== Screenshot Frame ===== */
.screenshot-wrapper {
  position: relative;
  border-radius: var(--radius-xl);
  overflow: hidden;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border-light);
  box-shadow: var(--shadow-lg);
  transition: all var(--transition-base);
}

.screenshot-wrapper:hover {
  transform: translateY(-4px);
  border-color: var(--color-border-accent);
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.6);
}

.screenshot-wrapper img {
  width: 100%;
  height: auto;
  display: block;
  border-radius: var(--radius-xl);
}

.screenshot-caption {
  padding: var(--space-4) var(--space-6);
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  background: var(--color-bg-card);
  border-top: 1px solid var(--color-border);
}

.screenshot-caption strong {
  color: var(--color-text-primary);
  font-weight: var(--weight-semibold);
}

/* Browser/Win chrome-like window frame */
.window-frame {
  position: relative;
  border-radius: var(--radius-xl);
  overflow: hidden;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border-light);
  box-shadow: var(--shadow-lg);
  transition: all var(--transition-base);
}

.window-frame:hover {
  transform: translateY(-4px);
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.6), var(--shadow-glow);
  border-color: var(--color-accent-dark);
}

.window-frame::before {
  content: '';
  display: block;
  height: 36px;
  background: linear-gradient(180deg, #1a2030 0%, #141a24 100%);
  border-bottom: 1px solid var(--color-border);
  position: relative;
}

.window-frame::after {
  content: '● ● ●';
  position: absolute;
  top: 12px;
  left: 16px;
  font-size: 10px;
  letter-spacing: 4px;
  color: var(--color-text-tertiary);
}

.window-frame img {
  width: 100%;
  height: auto;
  display: block;
}

/* Image with label below */
.image-block {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.image-label {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  font-weight: var(--weight-medium);
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.image-label::before {
  content: '';
  display: inline-block;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--color-accent);
}

/* Showcase layout: text + image */
.showcase {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-12);
  align-items: center;
  max-width: 1100px;
  margin: 0 auto;
}

.showcase-text {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.showcase-text .section-label {
  margin-bottom: 0;
}

.showcase-text h2 {
  font-family: var(--font-display);
  font-size: var(--text-3xl);
  font-weight: var(--weight-bold);
  line-height: var(--leading-tight);
  letter-spacing: -0.02em;
}

.showcase-text p {
  color: var(--color-text-secondary);
  font-size: var(--text-base);
  line-height: var(--leading-relaxed);
}

.showcase-text ul {
  list-style: none;
  margin-top: var(--space-2);
}

.showcase-text ul li {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  padding: var(--space-2) 0;
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
}

.showcase-text ul li::before {
  content: '✓';
  color: var(--color-green);
  font-weight: var(--weight-bold);
  flex-shrink: 0;
}

.showcase.reverse {
  grid-template-columns: 1fr 1fr;
}

.showcase.reverse .showcase-text {
  order: 2;
}

.showcase.reverse .showcase-image {
  order: 1;
}

/* Hero app preview */
.hero-app-preview {
  max-width: 1100px;
  margin: var(--space-16) auto 0;
  position: relative;
}

.hero-app-preview::before {
  content: '';
  position: absolute;
  top: -10%;
  left: 50%;
  transform: translateX(-50%);
  width: 80%;
  height: 80%;
  background: radial-gradient(ellipse, var(--color-accent-glow) 0%, transparent 60%);
  filter: blur(40px);
  pointer-events: none;
}

.hero-app-preview .window-frame {
  position: relative;
  z-index: 1;
}

/* Gallery grid */
.gallery-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-6);
  max-width: 1100px;
  margin: 0 auto;
}

/* Inline image at full width */
.full-image {
  width: 100%;
  max-width: 1100px;
  margin: 0 auto;
}

/* ===== Side-by-side layout ===== */
.split-2 {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-8);
  align-items: start;
}

@media (max-width: 768px) {
  .showcase,
  .showcase.reverse {
    grid-template-columns: 1fr;
  }

  .showcase.reverse .showcase-text,
  .showcase.reverse .showcase-image {
    order: initial;
  }

  .split-2,
  .gallery-grid {
    grid-template-columns: 1fr;
  }
}

/* ===== QQ Float Widget ===== */
.qq-float {
  position: fixed;
  bottom: 32px;
  right: 32px;
  z-index: 90;
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 8px;
}

.qq-float-btn {
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: linear-gradient(135deg, #12b7f5, #0d8ec4);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: 0 4px 20px rgba(18, 183, 245, 0.4);
  transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  border: none;
  position: relative;
}

.qq-float-btn:hover {
  transform: scale(1.1);
  box-shadow: 0 6px 28px rgba(18, 183, 245, 0.6);
}

.qq-float-btn svg {
  width: 30px;
  height: 30px;
  fill: #fff;
}

.qq-float-btn .badge {
  position: absolute;
  top: -2px;
  right: -2px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: #f87171;
  border: 2px solid var(--color-bg-primary);
  font-size: 0;
}

.qq-float-panel {
  position: absolute;
  bottom: 70px;
  right: 0;
  width: 280px;
  background: var(--color-bg-card);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-lg);
  overflow: hidden;
  opacity: 0;
  transform: translateY(10px) scale(0.95);
  pointer-events: none;
  transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

.qq-float-panel.open {
  opacity: 1;
  transform: translateY(0) scale(1);
  pointer-events: auto;
}

.qq-float-panel-header {
  background: linear-gradient(135deg, #12b7f5, #0d8ec4);
  padding: 16px 20px;
  color: #fff;
}

.qq-float-panel-header h4 {
  font-size: 15px;
  font-weight: 700;
  margin-bottom: 4px;
}

.qq-float-panel-header p {
  font-size: 12px;
  opacity: 0.9;
}

.qq-float-panel-body {
  padding: 16px 20px;
}

.qq-float-panel-body a {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px;
  border-radius: var(--radius-lg);
  background: var(--color-bg-tertiary);
  color: var(--color-text-primary);
  font-size: 14px;
  font-weight: 600;
  transition: all 0.15s;
  text-decoration: none;
}

.qq-float-panel-body a:hover {
  background: var(--color-bg-card-hover);
  transform: translateX(2px);
}

.qq-float-panel-body a svg {
  width: 24px;
  height: 24px;
  fill: #12b7f5;
  flex-shrink: 0;
}

.qq-float-panel-body .qq-num {
  font-size: 12px;
  color: var(--color-text-tertiary);
  font-weight: 400;
}

@media (max-width: 480px) {
  .qq-float {
    bottom: 20px;
    right: 20px;
  }
  .qq-float-btn {
    width: 48px;
    height: 48px;
  }
  .qq-float-panel {
    width: 260px;
  }
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .nav-links {
    position: fixed;
    top: var(--nav-height);
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--color-bg-primary);
    flex-direction: column;
    padding: var(--space-8);
    gap: var(--space-2);
    transform: translateX(100%);
    transition: transform var(--transition-base);
    z-index: 99;
  }

  .nav-links.open {
    transform: translateX(0);
  }

  .nav-links a {
    font-size: var(--text-lg);
    padding: var(--space-3) var(--space-4);
  }

  .nav-toggle {
    display: block;
  }

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

  .grid-2, .grid-3, .grid-4 {
    grid-template-columns: 1fr;
  }

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

  .page-header {
    padding: calc(var(--nav-height) + var(--space-12)) var(--space-4) var(--space-12);
  }
}

@media (max-width: 480px) {
  .footer-grid {
    grid-template-columns: 1fr;
  }

  .footer-bottom {
    flex-direction: column;
    gap: var(--space-4);
    text-align: center;
  }

  .stats-bar {
    grid-template-columns: 1fr;
  }
}

/* ===== Animations ===== */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(24px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-24px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.animate-in {
  animation: fadeInUp 0.6s cubic-bezier(0.22, 0.61, 0.36, 1) forwards;
  opacity: 0;
}

.animate-in:nth-child(1) { animation-delay: 0.05s; }
.animate-in:nth-child(2) { animation-delay: 0.1s; }
.animate-in:nth-child(3) { animation-delay: 0.15s; }
.animate-in:nth-child(4) { animation-delay: 0.2s; }
.animate-in:nth-child(5) { animation-delay: 0.25s; }
.animate-in:nth-child(6) { animation-delay: 0.3s; }

/* ===== Pricing Toggle ===== */
.pricing-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-4);
  margin-bottom: var(--space-12);
}

.pricing-toggle-label {
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
  font-weight: var(--weight-medium);
}

.pricing-toggle-label.active {
  color: var(--color-text-primary);
}

.pricing-toggle-switch {
  position: relative;
  width: 52px;
  height: 28px;
  background: var(--color-bg-tertiary);
  border-radius: 999px;
  cursor: pointer;
  border: 1px solid var(--color-border-light);
  transition: background var(--transition-fast);
}

.pricing-toggle-switch::after {
  content: '';
  position: absolute;
  top: 3px;
  left: 3px;
  width: 20px;
  height: 20px;
  background: var(--color-accent);
  border-radius: 50%;
  transition: transform var(--transition-base);
}

.pricing-toggle-switch.yearly::after {
  transform: translateX(24px);
}

.pricing-toggle-badge {
  font-size: var(--text-xs);
  padding: var(--space-1) var(--space-3);
  background: var(--color-green-glow);
  color: var(--color-green);
  border-radius: 999px;
  font-weight: var(--weight-semibold);
}

/* ===== Pricing Card ===== */
.pricing-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-2xl);
  padding: var(--space-10);
  text-align: center;
  transition: all var(--transition-base);
  position: relative;
}

.pricing-card.featured {
  border-color: var(--color-accent);
  background: var(--color-bg-elevated);
  box-shadow: var(--shadow-glow);
  transform: scale(1.03);
}

.pricing-card.featured:hover {
  transform: scale(1.03) translateY(-4px);
}

.pricing-badge {
  position: absolute;
  top: -14px;
  left: 50%;
  transform: translateX(-50%);
  padding: var(--space-1) var(--space-5);
  background: var(--color-gradient-accent);
  color: #1a1a1a;
  border-radius: 999px;
  font-size: var(--text-xs);
  font-weight: var(--weight-bold);
}

.pricing-card h3 {
  font-size: var(--text-2xl);
  font-weight: var(--weight-bold);
  margin-bottom: var(--space-2);
}

.pricing-card .price {
  font-family: var(--font-display);
  font-size: var(--text-5xl);
  font-weight: var(--weight-extrabold);
  margin: var(--space-6) 0;
  line-height: 1;
}

.pricing-card .price sub {
  font-size: var(--text-base);
  font-weight: var(--weight-normal);
  color: var(--color-text-tertiary);
}

.pricing-card .price-unit {
  font-size: var(--text-sm);
  color: var(--color-text-tertiary);
  margin-bottom: var(--space-2);
}

.pricing-card ul {
  list-style: none;
  text-align: left;
  margin: var(--space-8) 0;
}

.pricing-card ul li {
  padding: var(--space-2) 0;
  font-size: var(--text-sm);
  color: var(--color-text-secondary);
}

.pricing-card ul li::before {
  content: '✓ ';
  color: var(--color-green);
  font-weight: var(--weight-bold);
}

/* ===== FAQ ===== */
.faq-item {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  margin-bottom: var(--space-4);
  overflow: hidden;
  background: var(--color-bg-card);
  transition: all var(--transition-fast);
}

.faq-item:hover {
  border-color: var(--color-border-light);
}

.faq-question {
  width: 100%;
  padding: var(--space-6) var(--space-8);
  background: none;
  border: none;
  color: var(--color-text-primary);
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: var(--weight-semibold);
  text-align: left;
  cursor: pointer;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--space-4);
}

.faq-icon {
  font-size: 1.25rem;
  font-weight: var(--weight-light);
  color: var(--color-text-tertiary);
  transition: transform var(--transition-base);
  flex-shrink: 0;
}

.faq-item.active .faq-icon {
  transform: rotate(45deg);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height var(--transition-slow), padding var(--transition-slow);
}

.faq-item.active .faq-answer {
  max-height: 500px;
}

.faq-answer-inner {
  padding: 0 var(--space-8) var(--space-6);
  color: var(--color-text-secondary);
  font-size: var(--text-sm);
  line-height: var(--leading-relaxed);
}

/* ===== Download Card ===== */
.download-card {
  display: flex;
  align-items: center;
  gap: var(--space-8);
  padding: var(--space-8);
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  transition: all var(--transition-base);
}

.download-card:hover {
  border-color: var(--color-border-accent);
  box-shadow: var(--shadow-md);
}

.download-card-icon {
  width: 64px;
  height: 64px;
  border-radius: var(--radius-lg);
  background: var(--color-accent-glow);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 2rem;
  flex-shrink: 0;
}

.download-card-info h3 {
  font-size: var(--text-lg);
  font-weight: var(--weight-semibold);
  margin-bottom: var(--space-1);
}

.download-card-info p {
  font-size: var(--text-sm);
  color: var(--color-text-tertiary);
  margin-bottom: var(--space-4);
}

.download-meta {
  display: flex;
  gap: var(--space-4);
  font-size: var(--text-xs);
  color: var(--color-text-tertiary);
}

/* ===== Code Block ===== */
.code-block {
  background: #0d1117;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  overflow-x: auto;
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  line-height: 1.7;
  color: var(--color-text-secondary);
}

.code-block .comment { color: var(--color-text-muted); }
.code-block .key { color: var(--color-blue-light); }
.code-block .value { color: var(--color-green); }

/* ===== Architecture Diagram ===== */
.arch-diagram {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-4);
  padding: var(--space-12);
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  position: relative;
}

.arch-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-8);
  flex-wrap: wrap;
}

.arch-node {
  padding: var(--space-4) var(--space-8);
  background: var(--color-bg-elevated);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-lg);
  font-size: var(--text-sm);
  font-weight: var(--weight-semibold);
  text-align: center;
  min-width: 100px;
}

.arch-node.primary {
  border-color: var(--color-accent);
  background: var(--color-accent-glow);
}

.arch-node.blue {
  border-color: var(--color-blue);
  background: var(--color-blue-glow);
}

.arch-arrow {
  color: var(--color-text-muted);
  font-size: 1.25rem;
}

.arch-arrow-down {
  color: var(--color-text-muted);
  font-size: 1.5rem;
  line-height: 1;
}

/* ===== Contact Section ===== */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-6);
  margin-top: var(--space-12);
}

.contact-item {
  text-align: center;
  padding: var(--space-8);
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  transition: all var(--transition-base);
}

.contact-item:hover {
  border-color: var(--color-border-accent);
  transform: translateY(-2px);
}

.contact-item-icon {
  font-size: 2rem;
  margin-bottom: var(--space-4);
}

.contact-item h4 {
  font-size: var(--text-sm);
  font-weight: var(--weight-semibold);
  margin-bottom: var(--space-2);
}

.contact-item p {
  font-size: var(--text-sm);
  color: var(--color-text-tertiary);
}