/* ==========================================================================
   Livezala Learn — Design System & Stylesheet
   Domain: learn.livezala.com | Cloudflare Pages / Workers
   Aesthetic: Premium Warm-Dark & Clean Modern Minimal with Rich Imagery
   ========================================================================== */

:root {
  /* Color Tokens - Dark Default (matching livezala.com) */
  --bg: #0a0a0a;
  --bg-subtle: #0f0f0f;
  --surface: #141414;
  --surface-2: #1b1b1b;
  --surface-hover: #222222;
  --border: #242424;
  --border-2: #303030;
  
  --text: #f0f0f0;
  --text-2: #a3a3a3;
  --text-3: #6e6e6e;

  --accent: #ff8a3d;
  --accent-hover: #ff9b57;
  --accent-soft: rgba(255, 138, 61, 0.12);
  --accent-glow: rgba(255, 138, 61, 0.25);
  
  --amber: #f59e0b;
  --blue: #3b82f6;
  --green: #10b981;

  --font-main: 'Inter', 'IBM Plex Sans Thai', system-ui, -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', 'IBM Plex Mono', monospace;

  --radius-sm: 6px;
  --radius: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.4);
  --shadow: 0 4px 20px rgba(0, 0, 0, 0.6);
  --shadow-glow: 0 0 30px var(--accent-glow);

  color-scheme: dark;
}

html.light {
  --bg: #fafafa;
  --bg-subtle: #f4f4f5;
  --surface: #ffffff;
  --surface-2: #f0f0f2;
  --surface-hover: #e4e4e7;
  --border: #e2e2e5;
  --border-2: #d4d4d8;
  
  --text: #171717;
  --text-2: #525252;
  --text-3: #8a8a8a;

  --accent: #e8701f;
  --accent-hover: #d05f14;
  --accent-soft: rgba(232, 112, 31, 0.08);
  --accent-glow: rgba(232, 112, 31, 0.18);

  --shadow: 0 4px 20px rgba(0, 0, 0, 0.06);
  --shadow-glow: 0 0 25px var(--accent-glow);

  color-scheme: light;
}

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

html {
  scroll-behavior: smooth;
  scroll-padding-top: 80px;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-main);
  font-size: 16px;
  line-height: 1.65;
  background-color: var(--bg);
  color: var(--text);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

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

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

button {
  font-family: inherit;
}

.container {
  max-width: 1140px;
  margin: 0 auto;
  padding: 0 24px;
}

.text-center {
  text-align: center;
}

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

/* ==========================================================================
   Navigation Bar
   ========================================================================== */
.navbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: color-mix(in srgb, var(--bg) 85%, transparent);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
  transition: border-color 0.2s;
}

.nav-container {
  max-width: 1140px;
  margin: 0 auto;
  padding: 0 24px;
  height: 68px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-weight: 600;
  font-size: 17px;
  letter-spacing: -0.01em;
}

.brand-logo {
  width: 28px;
  height: 28px;
  flex-shrink: 0;
}

.brand-logo .logo-l {
  fill: var(--text);
}

.brand-logo .logo-dot {
  fill: var(--accent);
}

.brand-text {
  color: var(--text);
}

.brand-highlight {
  color: var(--accent);
  font-weight: 700;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
  font-size: 14.5px;
  color: var(--text-2);
}

.nav-links a {
  transition: color 0.15s;
}

.nav-links a:hover {
  color: var(--text);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 12px;
}

/* Icon Buttons */
.btn-icon {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text-2);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s, color 0.15s;
}

.btn-icon:hover {
  background: var(--surface-hover);
  color: var(--text);
  border-color: var(--border-2);
}

.btn-icon svg {
  width: 18px;
  height: 18px;
}

.icon-sun { display: none; }
.icon-moon { display: block; }
html.light .icon-sun { display: block; }
html.light .icon-moon { display: none; }

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-weight: 500;
  border-radius: var(--radius);
  cursor: pointer;
  transition: transform 0.12s, filter 0.15s, background-color 0.15s, border-color 0.15s;
  white-space: nowrap;
  line-height: 1;
}

.btn:active {
  transform: scale(0.98);
}

.btn-sm {
  height: 36px;
  padding: 0 16px;
  font-size: 13.5px;
}

.btn-lg {
  height: 48px;
  padding: 0 26px;
  font-size: 15.5px;
}

.btn-primary {
  background-color: var(--accent);
  color: #000000;
  font-weight: 600;
  border: 1px solid var(--accent);
}

.btn-primary:hover {
  background-color: var(--accent-hover);
  border-color: var(--accent-hover);
  box-shadow: 0 0 20px var(--accent-glow);
}

.btn-secondary {
  background-color: var(--surface-2);
  color: var(--text);
  border: 1px solid var(--border-2);
}

.btn-secondary:hover {
  background-color: var(--surface-hover);
  border-color: var(--text-3);
}

.btn-outline {
  background: transparent;
  color: var(--text-2);
  border: 1px solid var(--border-2);
}

.btn-outline:hover {
  color: var(--text);
  border-color: var(--accent);
  background: var(--accent-soft);
}

.arrow-icon {
  width: 16px;
  height: 16px;
  transition: transform 0.15s;
}

.btn:hover .arrow-icon {
  transform: translateX(3px);
}

/* ==========================================================================
   Hero Section
   ========================================================================== */
.hero-section {
  padding: 80px 0 64px;
  border-bottom: 1px solid var(--border);
  position: relative;
  overflow: hidden;
}

.hero-section::before {
  content: '';
  position: absolute;
  top: -120px;
  left: 50%;
  transform: translateX(-50%);
  width: 760px;
  height: 380px;
  background: radial-gradient(circle, var(--accent-soft) 0%, transparent 70%);
  pointer-events: none;
  z-index: 0;
}

.hero-section .container {
  position: relative;
  z-index: 1;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  border-radius: 99px;
  border: 1px solid var(--border-2);
  background: var(--surface);
  font-size: 13px;
  color: var(--text-2);
  margin-bottom: 24px;
}

.pulse-indicator {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background-color: var(--accent);
  box-shadow: 0 0 8px var(--accent);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0% { transform: scale(0.95); opacity: 0.8; }
  50% { transform: scale(1.3); opacity: 1; }
  100% { transform: scale(0.95); opacity: 0.8; }
}

.hero-title {
  font-size: 54px;
  line-height: 1.15;
  font-weight: 700;
  letter-spacing: -0.025em;
  margin-bottom: 20px;
}

.gradient-text {
  background: linear-gradient(135deg, var(--text) 30%, var(--accent) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero-subtitle {
  font-size: 18px;
  line-height: 1.7;
  color: var(--text-2);
  max-width: 740px;
  margin-bottom: 32px;
}

.hero-subtitle strong {
  color: var(--text);
  font-weight: 600;
}

/* ==========================================================================
   Voice Capsule Audio Player (Modern Voice Memo Waveform)
   ========================================================================== */
.voice-capsule {
  display: flex !important;
  align-items: center !important;
  gap: 14px !important;
  background: linear-gradient(135deg, rgba(255, 138, 61, 0.1) 0%, rgba(20, 20, 20, 0.95) 100%) !important;
  border: 1px solid rgba(255, 138, 61, 0.35) !important;
  border-radius: 20px !important;
  padding: 12px 18px !important;
  margin: 0 0 32px 0 !important;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.4), 0 0 20px rgba(255, 138, 61, 0.15) !important;
  width: 100% !important;
  max-width: 640px !important;
  box-sizing: border-box !important;
  cursor: pointer;
  transition: border-color 0.2s, box-shadow 0.2s;
}

html.light .voice-capsule {
  background: linear-gradient(135deg, rgba(232, 112, 31, 0.08) 0%, #ffffff 100%) !important;
  border-color: rgba(232, 112, 31, 0.3) !important;
  box-shadow: 0 4px 18px rgba(0, 0, 0, 0.06), 0 0 16px rgba(232, 112, 31, 0.12) !important;
}

.voice-capsule:hover {
  border-color: var(--accent) !important;
  box-shadow: 0 6px 26px rgba(0, 0, 0, 0.5), 0 0 28px rgba(255, 138, 61, 0.25) !important;
}

.voice-play-btn {
  width: 44px !important;
  min-width: 44px !important;
  max-width: 44px !important;
  height: 44px !important;
  min-height: 44px !important;
  max-height: 44px !important;
  border-radius: 50% !important;
  background: var(--accent) !important;
  color: #000000 !important;
  border: none !important;
  cursor: pointer !important;
  display: flex !important;
  align-items: center !important;
  justify-content: center !important;
  flex-shrink: 0 !important;
  box-shadow: 0 2px 10px rgba(255, 138, 61, 0.4) !important;
  transition: transform 0.12s, background-color 0.15s !important;
  padding: 0 !important;
}

.voice-play-btn:hover {
  transform: scale(1.06) !important;
  background: var(--accent-hover) !important;
}

.voice-play-btn svg {
  width: 18px !important;
  height: 18px !important;
}

.voice-play-btn .icon-pause {
  display: none !important;
}

.voice-play-btn.playing .icon-play {
  display: none !important;
}

.voice-play-btn.playing .icon-pause {
  display: block !important;
}

.voice-body {
  flex: 1 !important;
  min-width: 0 !important;
  display: flex !important;
  flex-direction: column !important;
  gap: 6px !important;
}

.voice-header-row {
  display: flex !important;
  justify-content: space-between !important;
  align-items: center !important;
  font-size: 13px !important;
  line-height: 1 !important;
}

.voice-label {
  font-weight: 600 !important;
  color: var(--text) !important;
  white-space: nowrap !important;
  overflow: hidden !important;
  text-overflow: ellipsis !important;
}

.voice-time {
  font-family: var(--font-mono) !important;
  font-size: 11.5px !important;
  color: var(--accent) !important;
  flex-shrink: 0 !important;
  margin-left: 8px !important;
}

/* Waveform */
.voice-waveform {
  display: flex !important;
  align-items: center !important;
  gap: 3px !important;
  height: 22px !important;
  width: 100% !important;
  cursor: pointer !important;
  padding: 2px 0 !important;
}

.voice-waveform span {
  flex: 1 !important;
  min-width: 2px !important;
  max-width: 6px !important;
  height: var(--h, 40%) !important;
  background: rgba(255, 255, 255, 0.22) !important;
  border-radius: 2px !important;
  transition: background-color 0.1s, height 0.15s ease !important;
}

html.light .voice-waveform span {
  background: rgba(0, 0, 0, 0.18) !important;
}

.voice-waveform span.active {
  background: var(--accent) !important;
}

.voice-capsule.playing .voice-waveform span.active {
  animation: voicePulse 1.2s infinite ease-in-out !important;
}

@keyframes voicePulse {
  0%, 100% { transform: scaleY(1); }
  50% { transform: scaleY(1.3); }
}

.voice-waveform span:nth-child(2n) { animation-delay: 0.15s !important; }
.voice-waveform span:nth-child(3n) { animation-delay: 0.3s !important; }
.voice-waveform span:nth-child(4n) { animation-delay: 0.45s !important; }

@media (max-width: 680px) {
  .voice-capsule {
    padding: 10px 14px !important;
    margin-bottom: 24px !important;
    gap: 12px !important;
  }
  .voice-play-btn {
    width: 40px !important;
    height: 40px !important;
    min-width: 40px !important;
    min-height: 40px !important;
  }
  .voice-play-btn svg {
    width: 16px !important;
    height: 16px !important;
  }
  .voice-label {
    font-size: 12.5px !important;
  }
  .voice-time {
    font-size: 11px !important;
  }
  .voice-waveform {
    height: 18px !important;
    gap: 2.5px !important;
  }
}

/* ==========================================================================
   Intent Selector & Simulator Box
   ========================================================================== */
.intent-box {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  padding: 24px;
  margin-bottom: 40px;
  box-shadow: var(--shadow);
}

.intent-header {
  margin-bottom: 14px;
  font-size: 13.5px;
  font-weight: 500;
  color: var(--text-3);
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.intent-chips {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-bottom: 20px;
}

.chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  border-radius: var(--radius);
  border: 1px solid var(--border-2);
  background: var(--surface-2);
  color: var(--text-2);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.15s ease;
}

.chip:hover {
  background: var(--surface-hover);
  color: var(--text);
  border-color: var(--text-3);
}

.chip.active {
  background: var(--accent-soft);
  color: var(--accent);
  border-color: var(--accent);
  font-weight: 600;
}

.chip-icon {
  font-size: 16px;
}

/* Simulator Card */
.simulator-card {
  border: 1px solid var(--border-2);
  border-radius: var(--radius-lg);
  background: var(--bg);
  overflow: hidden;
}

.sim-header {
  padding: 12px 18px;
  background: var(--surface-2);
  border-bottom: 1px solid var(--border);
  display: flex;
  align-items: center;
  gap: 12px;
}

.sim-dots {
  display: flex;
  gap: 6px;
}

.sim-dots span {
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--border-2);
}

.sim-dots span:nth-child(1) { background: #ef4444; }
.sim-dots span:nth-child(2) { background: #f59e0b; }
.sim-dots span:nth-child(3) { background: #10b981; }

.sim-title {
  font-size: 13px;
  color: var(--text-2);
  font-weight: 500;
  flex: 1;
}

.sim-badge {
  font-size: 11.5px;
  padding: 2px 8px;
  border-radius: 4px;
  background: var(--border);
  color: var(--text-3);
}

.sim-body {
  padding: 22px;
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.chat-row {
  display: flex;
  gap: 14px;
  align-items: flex-start;
}

.chat-avatar {
  width: 34px;
  height: 34px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  font-weight: 600;
  flex-shrink: 0;
}

.user-avatar {
  background: var(--surface-2);
  color: var(--text-2);
  border: 1px solid var(--border-2);
}

.ai-avatar {
  background: var(--accent);
  color: #000;
}

.ai-avatar svg {
  width: 18px;
  height: 18px;
}

.chat-bubble {
  padding: 14px 18px;
  border-radius: var(--radius-lg);
  font-size: 14.5px;
  line-height: 1.6;
  max-width: 820px;
}

.user-bubble {
  background: var(--surface-2);
  color: var(--text);
  border: 1px solid var(--border);
}

.ai-bubble {
  background: var(--surface);
  border: 1px solid var(--border-2);
  color: var(--text);
}

/* Image preview in simulator */
.sim-image-preview {
  margin-top: 14px;
  padding: 12px;
  border-radius: var(--radius);
  background: var(--bg);
  border: 1px solid var(--border);
}

.sim-image-badge {
  font-size: 12px;
  font-weight: 600;
  color: var(--accent);
  margin-bottom: 8px;
}

.sim-generated-thumb {
  width: 100%;
  max-width: 360px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-2);
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.4);
}

.bubble-actions {
  margin-top: 12px;
  padding-top: 10px;
  border-top: 1px dashed var(--border);
}

.btn-ghost-sm {
  background: transparent;
  border: none;
  color: var(--accent);
  font-size: 13px;
  display: inline-flex;
  align-items: center;
  gap: 6px;
  cursor: pointer;
  padding: 4px 8px;
  border-radius: var(--radius-sm);
  transition: background 0.12s;
}

.btn-ghost-sm:hover {
  background: var(--accent-soft);
}

.btn-ghost-sm svg {
  width: 15px;
  height: 15px;
}

/* Hero Actions & Meta */
.hero-actions {
  display: flex;
  gap: 14px;
  align-items: center;
  flex-wrap: wrap;
  margin-bottom: 24px;
}

.hero-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 13.5px;
  color: var(--text-3);
  flex-wrap: wrap;
}

.meta-dot {
  opacity: 0.5;
}

/* ==========================================================================
   Sections Common & Rich Cards with Images
   ========================================================================== */
.section {
  padding: 96px 0;
  border-bottom: 1px solid var(--border);
}

.bg-surface {
  background-color: var(--bg-subtle);
}

.section-header {
  margin-bottom: 48px;
}

.section-kicker {
  font-size: 13px;
  font-weight: 600;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  margin-bottom: 10px;
}

.section-title {
  font-size: 34px;
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.25;
  margin-bottom: 12px;
}

.section-desc {
  font-size: 16.5px;
  color: var(--text-2);
  max-width: 640px;
  line-height: 1.6;
}

/* Grid 3 */
.grid-3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

/* Feature Card with Images */
.feature-card.has-image {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: transform 0.2s ease, border-color 0.2s ease, box-shadow 0.2s ease;
}

.feature-card.has-image:hover {
  transform: translateY(-5px);
  border-color: var(--border-2);
  box-shadow: var(--shadow);
}

.card-image-wrap {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 10;
  overflow: hidden;
  background: var(--surface-2);
}

.card-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.3s ease;
}

.feature-card.has-image:hover .card-img {
  transform: scale(1.05);
}

.card-image-badge {
  position: absolute;
  top: 12px;
  right: 12px;
  font-size: 11.5px;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: 99px;
  backdrop-filter: blur(8px);
}

.bg-amber { background: rgba(245, 158, 11, 0.9); color: #000; }
.bg-blue { background: rgba(59, 130, 246, 0.9); color: #fff; }
.bg-green { background: rgba(16, 185, 129, 0.9); color: #000; }

.card-body {
  padding: 24px;
  display: flex;
  flex-direction: column;
  flex: 1;
}

.feature-title {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 12px;
  letter-spacing: -0.01em;
}

.feature-text {
  font-size: 14.5px;
  color: var(--text-2);
  line-height: 1.6;
  margin-bottom: 20px;
  flex: 1;
}

.feature-text em {
  color: var(--text);
  font-style: normal;
  background: var(--surface-2);
  padding: 2px 6px;
  border-radius: 4px;
}

.feature-tag {
  font-size: 12.5px;
  font-weight: 500;
  color: var(--accent);
  padding-top: 14px;
  border-top: 1px solid var(--border);
}

/* ==========================================================================
   Showcase Card (Mobile Learning)
   ========================================================================== */
.showcase-card {
  display: grid;
  grid-template-columns: 1.2fr 1fr;
  align-items: center;
  gap: 48px;
  padding: 40px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
}

.showcase-title {
  font-size: 32px;
  font-weight: 700;
  line-height: 1.25;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}

.showcase-desc {
  font-size: 15.5px;
  color: var(--text-2);
  line-height: 1.65;
  margin-bottom: 28px;
}

.showcase-bullets {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.bullet-item {
  display: flex;
  align-items: flex-start;
  gap: 12px;
}

.bullet-check {
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--accent-soft);
  color: var(--accent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 13px;
  flex-shrink: 0;
  margin-top: 2px;
}

.bullet-item strong {
  display: block;
  font-size: 15px;
  color: var(--text);
}

.bullet-item span {
  font-size: 13.5px;
  color: var(--text-2);
}

.showcase-image-wrap {
  position: relative;
  border-radius: var(--radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow);
  border: 1px solid var(--border-2);
}

.showcase-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.showcase-float-badge {
  position: absolute;
  bottom: 20px;
  left: 20px;
  right: 20px;
  background: color-mix(in srgb, var(--surface) 88%, transparent);
  backdrop-filter: blur(10px);
  border: 1px solid var(--border-2);
  border-radius: var(--radius);
  padding: 12px 18px;
  display: flex;
  align-items: center;
  gap: 14px;
}

.showcase-float-badge span {
  font-size: 24px;
}

.showcase-float-badge strong {
  display: block;
  font-size: 14px;
  color: var(--text);
}

.showcase-float-badge small {
  font-size: 12px;
  color: var(--accent);
}

/* ==========================================================================
   Curriculum / Lessons List
   ========================================================================== */
.lessons-list {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.lesson-card {
  display: grid;
  grid-template-columns: 60px 1fr auto;
  align-items: center;
  gap: 24px;
  padding: 24px 28px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  transition: border-color 0.15s, background-color 0.15s;
}

.lesson-card:hover {
  border-color: var(--border-2);
  background: var(--surface-2);
}

.lesson-index {
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 700;
  color: var(--text-3);
  text-align: center;
}

.lesson-meta {
  display: flex;
  gap: 12px;
  margin-bottom: 6px;
  font-size: 12.5px;
}

.lesson-time {
  color: var(--text-2);
}

.lesson-badge {
  padding: 2px 8px;
  border-radius: 99px;
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 600;
}

.lesson-title {
  font-size: 18px;
  font-weight: 600;
  margin-bottom: 6px;
  letter-spacing: -0.01em;
}

.lesson-desc {
  font-size: 14px;
  color: var(--text-2);
  max-width: 680px;
  line-height: 1.55;
}

/* ==========================================================================
   Prompt Grid (Interactive Playground)
   ========================================================================== */
.prompt-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.prompt-box {
  padding: 22px;
  border-radius: var(--radius-lg);
  background: var(--surface);
  border: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 12px;
  transition: border-color 0.15s;
}

.prompt-box:hover {
  border-color: var(--border-2);
}

.prompt-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.prompt-category {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-2);
}

.copy-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  border-radius: var(--radius-sm);
  background: var(--surface-2);
  border: 1px solid var(--border-2);
  color: var(--text);
  font-size: 12px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.15s;
}

.copy-btn:hover {
  background: var(--accent);
  color: #000;
  border-color: var(--accent);
}

.copy-btn svg {
  width: 14px;
  height: 14px;
}

.prompt-text {
  font-family: var(--font-mono);
  font-size: 13.5px;
  line-height: 1.6;
  color: var(--text);
  background: var(--bg);
  padding: 14px;
  border-radius: var(--radius);
  border: 1px solid var(--border);
}

/* ==========================================================================
   Certificate Showcase
   ========================================================================== */
.cert-card {
  display: grid;
  grid-template-columns: 1fr 1fr;
  align-items: center;
  gap: 48px;
  padding: 48px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
}

.cert-pill {
  display: inline-block;
  padding: 4px 12px;
  border-radius: 99px;
  background: var(--accent-soft);
  color: var(--accent);
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 16px;
}

.cert-details h2 {
  font-size: 30px;
  font-weight: 700;
  margin-bottom: 16px;
  letter-spacing: -0.02em;
}

.cert-details p {
  font-size: 15.5px;
  color: var(--text-2);
  line-height: 1.65;
  margin-bottom: 24px;
}

.cert-features {
  display: flex;
  flex-direction: column;
  gap: 10px;
  font-size: 14.5px;
  font-weight: 500;
}

.cert-preview {
  display: flex;
  justify-content: center;
}

.cert-mockup {
  width: 100%;
  max-width: 440px;
  aspect-ratio: 1.414 / 1;
  background: linear-gradient(135deg, #1f1f1f 0%, #111111 100%);
  border: 2px solid var(--accent);
  border-radius: 12px;
  padding: 20px;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.7), var(--shadow-glow);
  position: relative;
}

.cert-inner {
  height: 100%;
  border: 1px dashed rgba(255, 138, 61, 0.35);
  border-radius: 6px;
  padding: 24px 20px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-between;
  text-align: center;
}

.cert-head {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.15em;
  color: var(--accent);
}

.cert-sub {
  font-size: 11px;
  color: var(--text-3);
  margin-top: -6px;
}

.cert-course {
  font-size: 16px;
  font-weight: 700;
  color: var(--text);
}

.cert-name {
  font-size: 22px;
  font-weight: 700;
  color: var(--accent);
  border-bottom: 1px solid var(--border-2);
  padding-bottom: 4px;
  width: 80%;
}

.cert-footer {
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
  font-size: 10px;
  color: var(--text-3);
  font-family: var(--font-mono);
}

.cert-stamp {
  padding: 2px 8px;
  border: 1px solid var(--accent);
  color: var(--accent);
  border-radius: 3px;
  font-weight: 700;
}

/* ==========================================================================
   FAQ Accordion
   ========================================================================== */
.faq-accordion {
  max-width: 840px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.faq-item {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--surface);
  overflow: hidden;
  transition: border-color 0.15s;
}

.faq-item:hover {
  border-color: var(--border-2);
}

.faq-question {
  width: 100%;
  padding: 20px 24px;
  background: transparent;
  border: none;
  color: var(--text);
  font-size: 16px;
  font-weight: 600;
  text-align: left;
  display: flex;
  justify-content: space-between;
  align-items: center;
  cursor: pointer;
  gap: 16px;
}

.faq-icon {
  width: 18px;
  height: 18px;
  color: var(--text-3);
  transition: transform 0.2s ease;
  flex-shrink: 0;
}

.faq-item.open .faq-icon {
  transform: rotate(180deg);
  color: var(--accent);
}

.faq-answer {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.25s ease-out, padding 0.25s ease;
}

.faq-item.open .faq-answer {
  max-height: 200px;
  padding: 0 24px 20px;
}

.faq-answer p {
  font-size: 14.5px;
  color: var(--text-2);
  line-height: 1.65;
}

/* ==========================================================================
   CTA Section
   ========================================================================== */
.cta-section {
  background: linear-gradient(180deg, var(--bg) 0%, var(--bg-subtle) 100%);
  padding: 100px 0;
}

.cta-title {
  font-size: 38px;
  font-weight: 700;
  letter-spacing: -0.025em;
  margin-bottom: 14px;
}

.cta-subtitle {
  font-size: 17px;
  color: var(--text-2);
  max-width: 620px;
  margin: 0 auto 36px;
}

/* ==========================================================================
   Modal Dialog
   ========================================================================== */
.modal {
  position: fixed;
  inset: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s ease;
}

.modal.active {
  opacity: 1;
  pointer-events: auto;
}

.modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.75);
  backdrop-filter: blur(4px);
}

.modal-box {
  position: relative;
  z-index: 1;
  width: 100%;
  max-width: 580px;
  background: var(--surface);
  border: 1px solid var(--border-2);
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow);
  padding: 28px;
  transform: translateY(15px);
  transition: transform 0.2s ease;
}

.modal.active .modal-box {
  transform: translateY(0);
}

.modal-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 18px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--border);
}

.modal-title {
  font-size: 20px;
  font-weight: 700;
}

.modal-close {
  background: transparent;
  border: none;
  font-size: 26px;
  line-height: 1;
  color: var(--text-3);
  cursor: pointer;
}

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

.modal-body {
  font-size: 15px;
  color: var(--text-2);
  line-height: 1.65;
  margin-bottom: 24px;
}

.modal-footer {
  display: flex;
  justify-content: flex-end;
  gap: 12px;
}

/* ==========================================================================
   Footer
   ========================================================================== */
.footer {
  background: var(--bg);
  border-top: 1px solid var(--border);
  padding: 64px 0 32px;
}

.footer-content {
  display: grid;
  grid-template-columns: 1.5fr 2fr;
  gap: 48px;
  margin-bottom: 48px;
}

.footer-desc {
  font-size: 13.5px;
  color: var(--text-3);
  max-width: 360px;
  margin-top: 14px;
  line-height: 1.6;
}

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

.col-title {
  font-size: 13.5px;
  font-weight: 600;
  color: var(--text);
  margin-bottom: 14px;
  text-transform: uppercase;
  letter-spacing: 0.04em;
}

.link-col a {
  display: block;
  font-size: 14px;
  color: var(--text-2);
  margin-bottom: 10px;
  transition: color 0.12s;
}

.link-col a:hover {
  color: var(--accent);
}

.footer-bottom {
  padding-top: 24px;
  border-top: 1px solid var(--border);
  font-size: 13px;
  color: var(--text-3);
}

/* Toast */
.toast {
  position: fixed;
  bottom: 24px;
  right: 24px;
  background: var(--accent);
  color: #000;
  font-weight: 600;
  font-size: 14px;
  padding: 12px 20px;
  border-radius: var(--radius);
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.3);
  z-index: 2000;
  opacity: 0;
  transform: translateY(10px);
  pointer-events: none;
  transition: all 0.2s ease;
}

.toast.show {
  opacity: 1;
  transform: translateY(0);
}

/* ==========================================================================
   Responsive Breakpoints
   ========================================================================== */
@media (max-width: 900px) {
  .hero-title {
    font-size: 40px;
  }
  .grid-3 {
    grid-template-columns: 1fr;
  }
  .showcase-card {
    grid-template-columns: 1fr;
    padding: 30px;
    gap: 32px;
  }
  .prompt-grid {
    grid-template-columns: 1fr;
  }
  .cert-card {
    grid-template-columns: 1fr;
    padding: 32px;
  }
  .lesson-card {
    grid-template-columns: 48px 1fr;
  }
  .lesson-action {
    grid-column: 2 / -1;
    margin-top: 8px;
  }
  .footer-content {
    grid-template-columns: 1fr;
    gap: 36px;
  }
}

@media (max-width: 680px) {
  .nav-links {
    display: none;
  }
  .hide-mobile {
    display: none;
  }
  .hero-section {
    padding: 48px 0 52px;
  }
  .hero-title {
    font-size: 32px;
    line-height: 1.2;
  }
  .hero-subtitle {
    font-size: 15.5px;
  }
  
  /* Mobile Voice Capsule */
  .voice-capsule {
    padding: 10px 14px !important;
    margin-bottom: 24px !important;
    gap: 12px !important;
  }
  .voice-play-btn {
    width: 40px !important;
    height: 40px !important;
    min-width: 40px !important;
    min-height: 40px !important;
  }
  .voice-play-btn svg {
    width: 16px !important;
    height: 16px !important;
  }
  .voice-label {
    font-size: 12.5px !important;
  }
  .voice-time {
    font-size: 11px !important;
  }
  .voice-waveform {
    height: 18px !important;
    gap: 2.5px !important;
  }

  .intent-chips {
    flex-direction: column;
  }
  .chip {
    width: 100%;
    justify-content: flex-start;
  }
  .chat-row {
    flex-direction: column;
  }
  .hero-actions .btn {
    width: 100%;
  }
}