/* ---------- Pricing ---------- */
.pricing-grid {
  display: grid;
  grid-template-columns: 1fr 1.15fr 1fr 1fr;
  gap: var(--space-sm);
  max-width: 1160px;
  margin: 0 auto;
}

.features-grid-3col {
  grid-template-columns: repeat(3, 1fr);
}

/* ---------- Section Light ---------- */
.section-light {
  background: var(--color-dark);
}

/* ================================
   GCSClaw - Dark Theme Stylesheet
   Color: Blue → Purple → Red Gradient
   Font: Larger than standard (18px base)
   ================================ */

/* ---------- CSS Variables ---------- */
:root {
  /* Brand Colors */
  --color-blue: #2563EB;
  --color-blue-light: #3B82F6;
  --color-purple: #7C3AED;
  --color-purple-light: #8B5CF6;
  --color-red: #E11D48;
  --color-red-light: #F43F5E;

  /* Gradients */
  --gradient-primary: linear-gradient(135deg, #2563EB 0%, #7C3AED 50%, #E11D48 100%);
  --gradient-primary-soft: linear-gradient(135deg, #3B82F6 0%, #8B5CF6 50%, #F43F5E 100%);
  --gradient-text: linear-gradient(135deg, #3B82F6 0%, #A78BFA 50%, #A78BFA 100%);
  --gradient-card: linear-gradient(135deg, rgba(37, 99, 235, 0.15) 0%, rgba(124, 58, 237, 0.15) 50%, rgba(225, 29, 72, 0.15) 100%);
  --gradient-hero: radial-gradient(ellipse at 25% 15%, rgba(37, 99, 235, 0.35) 0%, transparent 55%),
                     radial-gradient(ellipse at 75% 55%, rgba(124, 58, 237, 0.35) 0%, transparent 55%),
                     radial-gradient(ellipse at 50% 95%, rgba(225, 29, 72, 0.25) 0%, transparent 50%);

  /* Neutrals */
  --color-dark: #050507;
  --color-dark-1: #0A0A0F;
  --color-dark-2: #0F0F17;
  --color-dark-3: #181824;
  --color-dark-4: #222230;
  --color-light: #FFFFFF;
  --color-text: #F8F8FB;
  --color-text-secondary: rgba(255, 255, 255, 0.7);
  --color-text-tertiary: rgba(255, 255, 255, 0.5);
  --color-border: rgba(255, 255, 255, 0.08);
  --color-border-light: rgba(255, 255, 255, 0.12);
  --color-border-strong: rgba(255, 255, 255, 0.18);

  /* Typography - Larger than standard */
  --font-base: 22px;
  --font-sm: 19px;
  --font-xs: 16px;
  --font-lg: 26px;
  --font-xl: 30px;
  --font-2xl: 40px;
  --font-3xl: 50px;
  --font-4xl: 64px;
  --font-5xl: 76px;
  --font-display: 92px;

  /* Spacing */
  --space-xs: 8px;
  --space-sm: 16px;
  --space-md: 24px;
  --space-lg: 40px;
  --space-xl: 64px;
  --space-2xl: 96px;
  --space-3xl: 128px;

  /* Radius */
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;

  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 40px rgba(124, 58, 237, 0.3);
  --shadow-glow-blue: 0 0 40px rgba(37, 99, 235, 0.3);
  --shadow-glow-red: 0 0 40px rgba(225, 29, 72, 0.25);

  /* Transitions */
  --transition-fast: 0.2s ease;
  --transition: 0.3s ease;
  --transition-slow: 0.5s ease;

  /* Layout */
  --container-max: 1240px;
  --navbar-height: 80px;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: var(--navbar-height);
  font-size: var(--font-base);
}

body {
  font-family: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, 'Segoe UI', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  font-size: var(--font-base);
  line-height: 1.7;
  color: var(--color-text);
  background: var(--color-dark);
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ---------- Mobile Polish (added 2026-07-26) ---------- */
html {
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
}
img, svg, video, canvas {
  max-width: 100%;
  height: auto;
}
a, button, .btn, .nav-toggle, .tab {
  touch-action: manipulation;
}
* {
  -webkit-tap-highlight-color: transparent;
}

a {
  text-decoration: none;
  color: inherit;
}

ul {
  list-style: none;
}

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

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
}

/* ---------- Container ---------- */
.container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

/* ---------- Section ---------- */
.section {
  padding: var(--space-3xl) 0;
  position: relative;
}

.section-dark {
  background: var(--color-dark-1);
}

.section-light {
  background: linear-gradient(180deg, var(--color-dark-1) 0%, var(--color-dark-2) 100%);
}

/* ---------- Section Header ---------- */
.section-header {
  text-align: center;
  margin-bottom: var(--space-2xl);
}

.section-label {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: var(--font-sm);
  font-weight: 700;
  letter-spacing: 0.2em;
  color: #A78BFA;
  text-transform: uppercase;
  margin-bottom: var(--space-md);
  padding: 8px 20px;
  background: rgba(124, 58, 237, 0.1);
  border: 1px solid rgba(124, 58, 237, 0.25);
  border-radius: var(--radius-full);
}

.section-title {
  font-size: var(--font-4xl);
  font-weight: 900;
  line-height: 1.2;
  color: var(--color-text);
  margin-bottom: var(--space-md);
  letter-spacing: -0.02em;
}

.section-desc {
  font-size: var(--font-lg);
  color: var(--color-text-tertiary);
  max-width: 640px;
  margin: 0 auto;
  line-height: 1.7;
}

/* ---------- Gradient Text ---------- */
.gradient-text {
  background: var(--gradient-text);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  display: inline-block;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  font-family: inherit;
  font-size: var(--font-base);
  font-weight: 600;
  padding: 12px 28px;
  border-radius: var(--radius-full);
  transition: all var(--transition);
  cursor: pointer;
  white-space: nowrap;
  border: 1px solid transparent;
}

.btn-sm {
  padding: 8px 20px;
  font-size: var(--font-sm);
}

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

.btn-primary {
  background: var(--gradient-primary);
  color: var(--color-light);
  box-shadow: var(--shadow-glow);
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 30px rgba(124, 58, 237, 0.5), 0 0 0 1px rgba(255, 255, 255, 0.1) inset;
}

.btn-light {
  background: var(--color-light);
  color: var(--color-dark);
  box-shadow: var(--shadow-md);
}

.btn-light:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg), 0 0 0 1px rgba(124, 58, 237, 0.2) inset;
}

.btn-outline {
  background: transparent;
  color: var(--color-text);
  border: 1px solid var(--color-border-light);
  box-shadow: 0 0 0 transparent;
}

.btn-outline:hover {
  background: rgba(255, 255, 255, 0.05);
  border-color: var(--color-border-strong);
  transform: translateY(-2px);
}

.btn-ghost {
  background: transparent;
  color: var(--color-text-secondary);
  padding: 8px 16px;
}

.btn-ghost:hover {
  color: var(--color-light);
}

/* ---------- Login Nav Button ---------- */
.btn-login {
  background: transparent;
  border: 1px solid var(--color-border-light);
  color: var(--color-text-secondary);
  border-radius: var(--radius-full);
  padding: 8px 24px;
  font-size: var(--font-base);
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition);
  font-family: inherit;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  white-space: nowrap;
}
.btn-login:hover {
  border-color: var(--color-purple);
  color: var(--color-text);
  background: rgba(124, 58, 237, 0.06);
}

/* ---------- Navbar ---------- */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--navbar-height);
  z-index: 1000;
  transition: all var(--transition);
  background: rgba(5, 5, 7, 0);
  backdrop-filter: blur(0px);
  border-bottom: 1px solid transparent;
}

.navbar.scrolled {
  background: rgba(5, 5, 7, 0.85);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--color-border);
  box-shadow: 0 4px 30px rgba(0, 0, 0, 0.3);
}

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

.nav-logo {
  display: flex;
  align-items: center;
  gap: 10px;
  z-index: 1001;
  flex-shrink: 0;
}

.nav-logo img {
  height: 44px;
  transition: var(--transition);
}

.nav-logo:hover img {
  filter: drop-shadow(0 0 12px rgba(124, 58, 237, 0.5));
}

.nav-menu {
  display: flex;
  gap: var(--space-md);
  align-items: center;
  flex: 1;
  justify-content: center;
}

.nav-link {
  font-size: var(--font-base);
  font-weight: 500;
  color: var(--color-text-tertiary);
  transition: color var(--transition);
  position: relative;
  padding: 6px 4px;
  white-space: nowrap;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--gradient-primary);
  transition: width var(--transition);
  border-radius: 2px;
}

.nav-link:hover,
.nav-link.active {
  color: var(--color-light);
}

.nav-link:hover::after,
.nav-link.active::after {
  width: 100%;
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  flex-shrink: 0;
}

.nav-login {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: var(--color-dark-4);
  border: 1px solid var(--color-border-light);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-secondary);
  transition: all var(--transition);
  flex-shrink: 0;
}

.nav-login:hover {
  background: var(--gradient-primary);
  color: var(--color-light);
  border-color: transparent;
  box-shadow: var(--shadow-glow);
}

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 8px;
  z-index: 1001;
}

.nav-toggle span {
  width: 26px;
  height: 3px;
  background: var(--color-text);
  border-radius: 3px;
  transition: all var(--transition);
}

.nav-toggle.active span:nth-child(1) {
  transform: translateY(8px) rotate(45deg);
}

.nav-toggle.active span:nth-child(2) {
  opacity: 0;
}

.nav-toggle.active span:nth-child(3) {
  transform: translateY(-8px) rotate(-45deg);
}

/* ---------- Hero Section ---------- */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  padding-top: var(--navbar-height);
  background: var(--color-dark);
}

.hero-bg {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 0;
  background: var(--gradient-hero);
}

.hero-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(100px);
  opacity: 0.45;
  animation: orbFloat 20s ease-in-out infinite;
}

.hero-orb-1 {
  width: 600px;
  height: 600px;
  background: var(--color-blue);
  top: -200px;
  left: -200px;
  animation-delay: 0s;
}

.hero-orb-2 {
  width: 700px;
  height: 700px;
  background: var(--color-red);
  top: 20%;
  right: -250px;
  animation-delay: 5s;
}

.hero-orb-3 {
  width: 500px;
  height: 500px;
  background: var(--color-red);
  bottom: -150px;
  left: 25%;
  animation-delay: 10s;
}

@keyframes orbFloat {
  0%, 100% { transform: translate(0, 0) scale(1); }
  33% { transform: translate(30px, -30px) scale(1.05); }
  66% { transform: translate(-20px, 20px) scale(0.95); }
}

.hero-grid {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-image:
    linear-gradient(rgba(255, 255, 255, 0.03) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.03) 1px, transparent 1px);
  background-size: 60px 60px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 30%, black 30%, transparent 100%);
  -webkit-mask-image: radial-gradient(ellipse 80% 60% at 50% 30%, black 30%, transparent 100%);
}

.hero-content {
  position: relative;
  z-index: 1;
  text-align: center;
  max-width: 900px;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 20px;
  background: rgba(255, 255, 255, 0.05);
  backdrop-filter: blur(10px);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-full);
  font-size: var(--font-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-lg);
}

.hero-badge .badge-icon {
  width: 18px;
  height: 18px;
  color: var(--color-blue-light);
}

.hero-logo {
  max-width: 320px;
  height: 80px;
  margin: 0 auto var(--space-lg);
  display: flex;
  align-items: center;
  justify-content: center;
  animation: logoFloat 6s ease-in-out infinite;
  filter: drop-shadow(0 0 40px rgba(124, 58, 237, 0.4));
}

.hero-logo img {
  max-width: 100%;
  max-height: 100%;
  object-fit: contain;
}

@keyframes logoFloat {
  0%, 100% { transform: translateY(0) rotate(0deg); }
  50% { transform: translateY(-12px) rotate(2deg); }
}

.hero-title {
  font-size: var(--font-display);
  font-weight: 900;
  line-height: 1.1;
  color: var(--color-text);
  margin-bottom: var(--space-md);
  letter-spacing: -0.02em;
}

.hero-subtitle {
  font-size: var(--font-xl);
  color: var(--color-text-secondary);
  line-height: 1.6;
  margin-bottom: var(--space-xl);
  max-width: 680px;
  margin-left: auto;
  margin-right: auto;
}

.hero-downloads {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
  justify-content: center;
  margin-bottom: var(--space-md);
}

.hero-mobile-links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
  justify-content: center;
  margin-bottom: var(--space-2xl);
}

.mobile-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: var(--font-base);
  color: var(--color-text-tertiary);
  font-weight: 500;
  padding: 10px 20px;
  border-radius: var(--radius-full);
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--color-border);
  transition: all var(--transition);
  cursor: pointer;
}

.mobile-link:hover {
  background: rgba(255, 255, 255, 0.08);
  color: var(--color-light);
  border-color: var(--color-border-light);
  transform: translateY(-2px);
}

.hero-scroll-hint {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  font-size: var(--font-sm);
  color: var(--color-text-tertiary);
  animation: scrollHint 2s ease-in-out infinite;
}

@keyframes scrollHint {
  0%, 100% { transform: translateY(0); opacity: 0.5; }
  50% { transform: translateY(10px); opacity: 1; }
}

/* ---------- Features Section ---------- */
.features {
  background: var(--color-dark-1);
  position: relative;
}

.features::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--color-border-light), transparent);
}

.features-grid {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: var(--space-md);
}

.feature-card {
  background: rgba(255, 255, 255, 0.03);
  border-radius: var(--radius-xl);
  padding: var(--space-xl) var(--space-md);
  border: 1px solid var(--color-border);
  transition: all var(--transition);
  position: relative;
  overflow: hidden;
  text-align: center;
}

.feature-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: var(--gradient-primary);
  opacity: 0;
  transition: opacity var(--transition);
}

.feature-card:hover {
  transform: translateY(-8px);
  background: rgba(255, 255, 255, 0.06);
  border-color: rgba(124, 58, 237, 0.3);
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.4), var(--shadow-glow);
}

.feature-card:hover::before {
  opacity: 1;
}

.feature-icon {
  width: 72px;
  height: 72px;
  border-radius: var(--radius-lg);
  background: var(--gradient-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto var(--space-md);
  color: var(--color-light);
  transition: all var(--transition);
  box-shadow: 0 8px 32px rgba(124, 58, 237, 0.35);
}

.feature-card:hover .feature-icon {
  transform: scale(1.1) rotate(-3deg);
  box-shadow: 0 12px 40px rgba(124, 58, 237, 0.5);
}

.feature-emoji {
  font-size: 36px;
  line-height: 1;
}

.feature-tag {
  display: inline-block;
  font-size: var(--font-xs);
  font-weight: 700;
  color: var(--color-light);
  background: var(--gradient-primary);
  padding: 4px 14px;
  border-radius: var(--radius-full);
  margin-bottom: var(--space-sm);
}

.feature-title {
  font-size: var(--font-lg);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-sm);
  line-height: 1.4;
}

.feature-desc {
  font-size: var(--font-sm);
  color: var(--color-text-tertiary);
  line-height: 1.6;
}

/* ---------- How It Works ---------- */
.how-it-works {
  background: linear-gradient(180deg, var(--color-dark-1) 0%, var(--color-dark-2) 100%);
}

.steps-container {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-xl);
  position: relative;
  max-width: 1000px;
  margin: 0 auto;
}

.steps-line {
  position: absolute;
  top: 40px;
  left: 18%;
  right: 18%;
  height: 3px;
  background: var(--gradient-primary);
  opacity: 0.25;
  border-radius: 2px;
}

.step-item {
  text-align: center;
  position: relative;
  z-index: 1;
}

.step-number {
  width: 60px;
  height: 60px;
  border-radius: 50%;
  background: var(--gradient-primary);
  color: var(--color-light);
  font-size: var(--font-xl);
  font-weight: 900;
  display: flex;
  align-items: center;
  justify-content: center;
  margin: 0 auto var(--space-md);
  box-shadow: var(--shadow-glow);
  position: relative;
  border: 3px solid var(--color-dark-2);
}

.step-icon {
  color: var(--color-purple-light);
  margin-bottom: var(--space-sm);
  display: flex;
  justify-content: center;
}

.step-title {
  font-size: var(--font-xl);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-sm);
}

.step-desc {
  font-size: var(--font-base);
  color: var(--color-text-tertiary);
  line-height: 1.7;
  max-width: 280px;
  margin: 0 auto;
}

/* ---------- Use Cases ---------- */
.use-cases {
  position: relative;
  overflow: hidden;
  background: var(--color-dark-2);
}

.use-cases::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: radial-gradient(ellipse at 50% 0%, rgba(124, 58, 237, 0.1) 0%, transparent 60%);
  pointer-events: none;
}

.usecase-tabs {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  justify-content: center;
  margin-bottom: var(--space-2xl);
  position: relative;
  z-index: 1;
}

.usecase-tab {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 24px;
  border-radius: var(--radius-full);
  font-size: var(--font-base);
  font-weight: 500;
  color: var(--color-text-tertiary);
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--color-border);
  transition: all var(--transition);
}

.usecase-tab:hover {
  color: var(--color-light);
  background: rgba(255, 255, 255, 0.08);
  border-color: var(--color-border-light);
}

.usecase-tab.active {
  color: var(--color-light);
  background: var(--gradient-primary);
  border-color: transparent;
  box-shadow: var(--shadow-glow);
}

.usecase-panels {
  position: relative;
  min-height: 420px;
  z-index: 1;
}

.usecase-panel {
  display: none;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-2xl);
  align-items: center;
}

.usecase-panel.active {
  display: grid;
  animation: panelFadeIn 0.5s ease;
}

@keyframes panelFadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

.usecase-chat {
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-xl);
  overflow: hidden;
  backdrop-filter: blur(10px);
  box-shadow: var(--shadow-md);
}

.chat-header {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: var(--space-md) var(--space-lg);
  background: rgba(255, 255, 255, 0.04);
  border-bottom: 1px solid var(--color-border);
  font-size: var(--font-base);
  font-weight: 600;
  color: var(--color-text-secondary);
}

.chat-avatar {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-light);
}

.wechat-avatar {
  background: #07C160;
}

.chat-body {
  padding: var(--space-lg);
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.chat-msg {
  display: flex;
}

.chat-msg-user {
  justify-content: flex-end;
}

.chat-msg-bot {
  justify-content: flex-start;
}

.chat-bubble {
  max-width: 85%;
  padding: var(--space-sm) var(--space-md);
  border-radius: var(--radius-lg);
  font-size: var(--font-base);
  line-height: 1.6;
}

.chat-bubble-user {
  background: var(--gradient-primary);
  color: var(--color-light);
  border-bottom-right-radius: 4px;
  box-shadow: var(--shadow-glow);
}

.chat-bubble-bot {
  background: rgba(255, 255, 255, 0.06);
  color: var(--color-text-secondary);
  border: 1px solid var(--color-border);
  border-bottom-left-radius: 4px;
}

.chat-status {
  padding: 4px 0;
  font-size: var(--font-base);
}

.chat-status.success {
  color: #4ADE80;
  font-weight: 600;
}

.usecase-info {
  padding: var(--space-lg);
}

.usecase-icon-large {
  font-size: 64px;
  line-height: 1;
  margin-bottom: var(--space-md);
}

.usecase-title {
  font-size: var(--font-2xl);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-md);
}

.usecase-desc {
  font-size: var(--font-lg);
  color: var(--color-text-tertiary);
  line-height: 1.7;
  margin-bottom: var(--space-lg);
}

.usecase-features {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.usecase-features li {
  font-size: var(--font-base);
  color: var(--color-text-secondary);
  display: flex;
  align-items: center;
  gap: 8px;
}

/* ---------- Stats Section ---------- */
.stats {
  background: var(--color-dark);
  padding: var(--space-2xl) 0;
  position: relative;
}

.stats::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--color-border-light), transparent);
}

.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: var(--space-lg);
  text-align: center;
}

.stat-item {
  position: relative;
  padding: var(--space-md) 0;
}

.stat-item:not(:last-child)::after {
  content: '';
  position: absolute;
  right: calc(var(--space-lg) * -0.5);
  top: 20%;
  bottom: 20%;
  width: 1px;
  background: var(--color-border);
}

.stat-number {
  display: inline;
  font-size: var(--font-5xl);
  font-weight: 900;
  background: var(--gradient-text);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  line-height: 1;
}

.stat-suffix {
  display: inline;
  font-size: var(--font-3xl);
  font-weight: 700;
  color: var(--color-purple-light);
  line-height: 1;
}

.stat-label {
  font-size: var(--font-base);
  color: var(--color-text-tertiary);
  margin-top: var(--space-sm);
}

/* ---------- CTA Section ---------- */
.cta-section {
  position: relative;
  padding: var(--space-3xl) 0;
  background: linear-gradient(180deg, var(--color-dark-2) 0%, var(--color-dark-1) 100%);
  overflow: hidden;
}

.cta-bg {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 0;
}

.cta-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(120px);
  opacity: 0.35;
}

.cta-orb-1 {
  width: 500px;
  height: 500px;
  background: var(--color-blue);
  top: -200px;
  left: 10%;
}

.cta-orb-2 {
  width: 600px;
  height: 600px;
  background: var(--color-red);
  bottom: -300px;
  right: 5%;
}

.cta-content {
  position: relative;
  z-index: 1;
  text-align: center;
}

.cta-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 20px;
  background: rgba(255, 255, 255, 0.04);
  backdrop-filter: blur(10px);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-full);
  font-size: var(--font-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-lg);
}

.cta-title {
  font-size: var(--font-5xl);
  font-weight: 900;
  color: var(--color-text);
  margin-bottom: var(--space-md);
  line-height: 1.15;
}

.cta-subtitle {
  font-size: var(--font-xl);
  color: var(--color-text-tertiary);
  margin-bottom: var(--space-xl);
}

.cta-downloads {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
  justify-content: center;
  margin-bottom: var(--space-md);
}

.cta-mobile-links {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-md);
  justify-content: center;
  margin-bottom: var(--space-md);
}

/* ---------- Footer ---------- */
.footer {
  background: var(--color-dark);
  color: var(--color-text-tertiary);
  padding: var(--space-2xl) 0 var(--space-lg);
  border-top: 1px solid var(--color-border);
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: var(--space-xl);
  margin-bottom: var(--space-xl);
}

.footer-brand img {
  height: 44px;
  margin-bottom: var(--space-md);
}

.footer-desc {
  font-size: var(--font-base);
  color: var(--color-text-tertiary);
  line-height: 1.7;
  margin-bottom: var(--space-md);
  max-width: 320px;
}

.footer-social {
  display: flex;
  gap: var(--space-sm);
}

.social-link {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--color-border);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--color-text-tertiary);
  transition: all var(--transition);
}

.social-link:hover {
  background: var(--gradient-primary);
  color: var(--color-light);
  border-color: transparent;
  transform: translateY(-2px);
  box-shadow: var(--shadow-glow);
}

.footer-title {
  font-size: var(--font-base);
  font-weight: 700;
  color: var(--color-text);
  margin-bottom: var(--space-md);
}

.footer-links li {
  margin-bottom: var(--space-sm);
}

.footer-links a {
  font-size: var(--font-base);
  color: var(--color-text-tertiary);
  transition: color var(--transition);
}

.footer-links a:hover {
  color: var(--color-purple-light);
}

.footer-bottom {
  border-top: 1px solid var(--color-border);
  padding-top: var(--space-lg);
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: var(--font-sm);
  color: var(--color-text-tertiary);
}

.footer-icp {
  font-size: var(--font-sm);
  color: var(--color-text-tertiary);
}

/* ---------- Scroll Reveal Animation ---------- */
.reveal {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.reveal.visible {
  opacity: 1;
  transform: translateY(0);
}


/* ===========================
   RESPONSIVE - MOBILE FIRST
   =========================== */

/* 1200px - Small desktop */
@media (max-width: 1200px) {
  .nav-menu { gap: var(--space-sm); }
  .features-grid { grid-template-columns: repeat(3, 1fr); }
  .features-grid-3col { grid-template-columns: repeat(2, 1fr); }
  .pricing-grid { grid-template-columns: repeat(2, 1fr); }
}

/* 1024px - Tablet landscape */
@media (max-width: 1024px) {
  :root {
    --font-display: 60px;
    --font-5xl: 56px;
    --font-4xl: 44px;
  }
  .features-grid { grid-template-columns: repeat(2, 1fr); }
  .features-grid-3col { grid-template-columns: repeat(2, 1fr); }
  .pricing-grid { grid-template-columns: repeat(2, 1fr); }
  .usecase-panel.active { grid-template-columns: 1fr; gap: var(--space-lg); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .footer-brand { grid-column: 1 / -1; }
}

/* 900px - Mobile nav toggle */
@media (max-width: 900px) {
  .nav-menu {
    position: fixed; top: 0; left: 0; right: 0; bottom: 0;
    background: var(--color-dark-1);
    flex-direction: column; justify-content: center; align-items: center;
    gap: var(--space-lg); transform: translateX(100%);
    transition: transform var(--transition); z-index: 999;
  }
  .nav-menu.active { transform: translateX(0); }
  .nav-link { font-size: var(--font-2xl); }
  .nav-actions { gap: 8px; }
  .nav-toggle { display: flex; }
  .nav-actions .btn-login { display: flex; }
}

/* ============================================================
   RESPONSIVE - TABLET & MOBILE (content sections)
   These complement the existing 1200/1024/900 nav + auth rules.
   ============================================================ */

/* 768px - Tablet / large phone */
@media (max-width: 768px) {
  :root {
    --font-base: 18px;
    --font-sm: 17px;
    --font-xs: 15px;
    --font-lg: 21px;
    --font-xl: 24px;
    --font-2xl: 30px;
    --font-3xl: 36px;
    --font-4xl: 34px;
    --font-5xl: 44px;
    --font-display: 46px;
    --space-lg: 24px;
    --space-xl: 40px;
    --space-2xl: 56px;
    --space-3xl: 72px;
  }
  .container { padding: 0 var(--space-md); }
  .section { padding: var(--space-2xl) 0; }
  .section-header { margin-bottom: var(--space-xl); }

  .hero { min-height: auto; padding: calc(var(--navbar-height) + var(--space-lg)) 0 var(--space-2xl); }
  .hero-title { font-size: var(--font-display); }
  .hero-subtitle { font-size: var(--font-lg); margin-bottom: var(--space-lg); }
  .hero-logo { max-width: 240px; height: 64px; }

  .features-grid { grid-template-columns: repeat(2, 1fr) !important; gap: var(--space-md); }
  .feature-card { padding: var(--space-lg) var(--space-sm); }

  .steps-container { grid-template-columns: 1fr; gap: var(--space-lg); }
  .steps-line { display: none; }
  .step-desc { max-width: none; }

  .usecase-panel.active { gap: var(--space-lg); }
  .usecase-info { padding: var(--space-md) 0; }

  .pricing-grid { grid-template-columns: repeat(2, 1fr) !important; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); gap: var(--space-md); }
  .stat-number { font-size: 44px; }

  .footer-grid { grid-template-columns: 1fr 1fr; gap: var(--space-lg); }
  .cta-title { font-size: var(--font-5xl); }

  .nav-link { font-size: var(--font-xl); }
}

/* 600px - Phone landscape */
@media (max-width: 600px) {
  .features-grid { grid-template-columns: 1fr !important; }
  .pricing-grid { grid-template-columns: 1fr !important; }
}

/* 480px - Phone portrait */
@media (max-width: 480px) {
  :root {
    --font-base: 16px;
    --font-sm: 15px;
    --font-lg: 19px;
    --font-xl: 22px;
    --font-2xl: 26px;
    --font-3xl: 30px;
    --font-4xl: 28px;
    --font-5xl: 34px;
    --font-display: 38px;
    --space-md: 16px;
    --space-lg: 20px;
    --space-xl: 28px;
    --space-2xl: 40px;
    --space-3xl: 56px;
  }
  .container { padding: 0 var(--space-sm); }
  .section { padding: var(--space-2xl) 0; }

  .hero-logo { max-width: 200px; height: 56px; }
  .hero-title { font-size: var(--font-display); }
  .hero-badge { font-size: var(--font-sm); padding: 6px 14px; }
  .hero-downloads,
  .hero-mobile-links,
  .cta-downloads,
  .cta-mobile-links { gap: var(--space-sm); }
  .btn-lg { padding: 14px 24px; font-size: var(--font-base); }
  .nav-actions .btn { min-height: 44px; }
  .hero-downloads .btn,
  .cta-downloads .btn { width: 100%; max-width: 340px; }

  .section-title { font-size: var(--font-4xl); }
  .section-desc { font-size: var(--font-base); }

  .features-grid { grid-template-columns: 1fr !important; }
  .feature-card { padding: var(--space-lg) var(--space-sm); }

  .usecase-icon-large { font-size: 48px; }
  .usecase-title { font-size: var(--font-2xl); }
  .usecase-desc { font-size: var(--font-base); }

  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .stat-number { font-size: 38px; }
  .stat-suffix { font-size: var(--font-2xl); }

  .footer-grid { grid-template-columns: 1fr; gap: var(--space-md); }
  .footer-bottom { flex-direction: column; gap: var(--space-sm); text-align: center; }
  .cta-title { font-size: var(--font-5xl); }
  .cta-subtitle { font-size: var(--font-lg); }
}

/* 360px - Small phone */
@media (max-width: 360px) {
  :root {
    --font-display: 32px;
    --font-4xl: 24px;
    --font-5xl: 28px;
  }
  .hero-title { font-size: var(--font-display); }
}

/* ================================
   Auth Modal / Login Overlay
   ================================ */
.auth-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(0, 0, 0, 0.75);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  z-index: 9999;
  display: flex;
  align-items: center;
  justify-content: center;
}
.auth-overlay[style*="display: none"],
.auth-overlay[style*="display:none"] {
  display: none !important;
}
.auth-container {
  display: flex;
  background: var(--color-dark-2);
  border: 1px solid var(--color-dark-4);
  border-radius: 16px;
  overflow: hidden;
  width: 780px;
  max-width: 95vw;
  position: relative;
  box-shadow: 0 25px 80px rgba(0, 0, 0, 0.6), 0 0 0 1px rgba(124, 58, 237, 0.1);
}
.auth-close {
  position: absolute;
  top: 12px;
  right: 16px;
  background: none;
  border: none;
  color: var(--color-text-dim);
  font-size: 28px;
  cursor: pointer;
  z-index: 10;
  width: 36px;
  height: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 8px;
  transition: all 0.2s;
  line-height: 1;
}
.auth-close:hover {
  color: var(--color-light);
  background: var(--color-dark-4);
}
.auth-left {
  flex: 1;
  padding: 48px 40px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
}
.auth-logo {
  margin-bottom: 20px;
}
.auth-logo img {
  height: 48px;
}
.auth-title {
  font-size: var(--font-xl);
  font-weight: 600;
  color: var(--color-light);
  text-align: center;
  margin-bottom: 28px;
}
.auth-wechat-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  width: 100%;
  max-width: 320px;
  padding: 12px 24px;
  background: var(--gradient-primary);
  color: var(--color-light);
  border: none;
  border-radius: 10px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s;
}
.auth-wechat-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 8px 24px rgba(124, 58, 237, 0.35);
}
.auth-divider {
  display: flex;
  align-items: center;
  width: 100%;
  max-width: 320px;
  margin: 20px 0;
  color: var(--color-text-dim);
  font-size: 13px;
}
.auth-divider::before,
.auth-divider::after {
  content: "";
  flex: 1;
  height: 1px;
  background: var(--color-dark-4);
}
.auth-divider span {
  padding: 0 16px;
}
.auth-form-inline {
  width: 100%;
  max-width: 320px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}
.auth-input-group {
  width: 100%;
}
.auth-input {
  width: 100%;
  padding: 12px 16px;
  background: var(--color-dark-3);
  border: 1px solid var(--color-dark-4);
  border-radius: 8px;
  color: var(--color-light);
  font-size: 15px;
  outline: none;
  transition: border-color 0.2s;
  box-sizing: border-box;
}
.auth-input::placeholder {
  color: var(--color-text-dim);
}
.auth-input:focus {
  border-color: var(--color-purple);
  box-shadow: 0 0 0 3px rgba(124, 58, 237, 0.15);
}
.auth-submit-btn {
  width: 100%;
  padding: 12px;
  background: var(--gradient-primary);
  color: var(--color-light);
  border: none;
  border-radius: 10px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s;
  margin-top: 4px;
}
.auth-submit-btn:hover {
  transform: translateY(-1px);
  box-shadow: 0 8px 24px rgba(124, 58, 237, 0.35);
}
.auth-submit-btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
  transform: none;
}
.auth-msg {
  text-align: center;
  font-size: 14px;
  padding: 8px 16px;
  border-radius: 8px;
  margin-top: 12px;
  max-width: 320px;
  width: 100%;
}
.auth-msg.success {
  color: #10B981;
  background: rgba(16, 185, 129, 0.1);
  border: 1px solid rgba(16, 185, 129, 0.2);
}
.auth-msg.error {
  color: #EF4444;
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid rgba(239, 68, 68, 0.2);
}
.auth-right {
  width: 240px;
  flex-shrink: 0;
  background: var(--color-dark-3);
  padding: 40px 28px;
  display: flex;
  flex-direction: column;
  border-left: 1px solid var(--color-dark-4);
}
.auth-dl-title {
  font-size: 16px;
  font-weight: 600;
  color: var(--color-light);
  margin-bottom: 16px;
  text-align: center;
}
.auth-dl-list {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.auth-dl-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 12px;
  color: var(--color-text);
  text-decoration: none;
  border-radius: 8px;
  font-size: 13px;
  transition: all 0.2s;
}
.auth-dl-item:hover {
  background: var(--color-dark-4);
  color: var(--color-light);
}
.auth-dl-item.disabled {
  opacity: 0.4;
  cursor: default;
  pointer-events: none;
}

@media (max-width: 768px) {
  .auth-container { flex-direction: column; width: 92vw; }
  .auth-right { width: 100%; border-left: none; border-top: 1px solid var(--color-border); padding: 32px 24px; }
  .auth-left { padding: 36px 24px; }
  .auth-dl-list { flex-direction: row; flex-wrap: wrap; gap: 8px; }
  .auth-dl-item { font-size: 13px; padding: 8px 12px; }
  .auth-wechat-btn { max-width: 100%; }
  .auth-form-inline { max-width: 100%; }
}

@media (max-width: 480px) {
  .auth-left { padding: 28px 20px; }
  .auth-title { font-size: var(--font-xl); }
  .auth-logo img { height: 40px; }
  .btn-login { padding: 6px 16px; font-size: 14px; }
}