/**
 * Subz Landing Page Stylesheet
 * 100% Pure Light Mode | Apple x Google Minimalist Standards
 * Typography: Plus Jakarta Sans
 */

:root {
  --bg-main: #FFFFFF;
  --bg-subtle: #F8FAFC;
  --bg-card: #FFFFFF;
  --border-light: #E2E8F0;
  --border-subtle: #F1F5F9;
  --text-main: #0F172A;
  --text-muted: #475569;
  --text-subtle: #94A3B8;
  --primary-blue: #006CF2;
  --primary-hover: #0056CC;
  --accent-amber: #F59E0B;
  --accent-amber-bg: rgba(245, 158, 11, 0.12);
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.05), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px -5px rgba(15, 23, 42, 0.08), 0 8px 10px -6px rgba(15, 23, 42, 0.04);
}

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

html {
  scroll-behavior: smooth;
}

body {
  background-color: var(--bg-main);
  color: var(--text-main);
  font-family: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

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

/* Typography Helpers */
h1, h2, h3, h4 {
  color: var(--text-main);
  font-weight: 800;
  letter-spacing: -0.025em;
  line-height: 1.2;
}

.accent-text {
  color: var(--primary-blue);
}

.surfboard-gradient {
  color: var(--text-main);
  font-weight: 700;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 22px;
  font-size: 14.5px;
  font-weight: 600;
  border-radius: 10px;
  text-decoration: none;
  transition: all 0.18s cubic-bezier(0.16, 1, 0.3, 1);
  cursor: pointer;
}

.btn-primary {
  background-color: var(--primary-blue);
  color: #FFFFFF;
  border: 1px solid var(--primary-blue);
  box-shadow: 0 2px 4px rgba(0, 108, 242, 0.25);
}

.btn-primary:hover {
  background-color: var(--primary-hover);
  border-color: var(--primary-hover);
  transform: translateY(-1px);
  box-shadow: 0 6px 12px rgba(0, 108, 242, 0.25);
}

.btn-secondary {
  background-color: var(--bg-subtle);
  color: var(--text-main);
  border: 1px solid var(--border-light);
}

.btn-secondary:hover {
  background-color: #FFFFFF;
  border-color: #CBD5E1;
  transform: translateY(-1px);
}

.btn-nav {
  padding: 8px 16px;
  font-size: 13.5px;
  background-color: var(--primary-blue);
  color: #FFFFFF;
  border: 1px solid var(--primary-blue);
}

.btn-nav:hover {
  background-color: var(--primary-hover);
}

/* Navbar */
.navbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  background-color: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border-subtle);
}

.nav-container {
  max-width: 1140px;
  margin: 0 auto;
  padding: 14px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: flex;
  align-items: center;
  gap: 9px;
  text-decoration: none;
}

.brand-logo {
  border-radius: 7px;
}

.brand-text {
  font-size: 18px;
  font-weight: 800;
  letter-spacing: 0.06em;
  color: var(--text-main);
}

.brand-by {
  font-size: 11.5px;
  color: var(--text-subtle);
  margin-left: 2px;
}

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

.nav-links a {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.15s ease;
}

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

/* Hero Section */
.hero {
  padding: 96px 0 68px;
  text-align: center;
  background: radial-gradient(circle at 50% 0%, #F1F7FE 0%, #FFFFFF 70%);
}

.hero-title {
  font-size: 54px;
  margin-bottom: 20px;
  letter-spacing: -0.035em;
}

.hero-subtitle {
  font-size: 19px;
  color: var(--text-muted);
  max-width: 740px;
  margin: 0 auto 36px;
  line-height: 1.55;
}

.hero-buttons {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-bottom: 32px;
  flex-wrap: wrap;
}

.hero-trust {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 24px;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-subtle);
  flex-wrap: wrap;
}

/* Interactive Demo Stage */
.demo-section {
  padding: 60px 0 90px;
}

.section-header {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 48px;
}

.section-tag {
  display: inline-block;
  font-size: 11.5px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--primary-blue);
  margin-bottom: 10px;
}

.section-title {
  font-size: 36px;
  margin-bottom: 12px;
}

.section-subtitle {
  font-size: 17px;
  color: var(--text-muted);
}

.demo-card-stage {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 36px;
  flex-wrap: wrap;
}

/* Mock Player */
.player-mockup {
  width: 580px;
  background-color: #0F172A;
  border-radius: 14px;
  overflow: hidden;
  box-shadow: var(--shadow-xl);
  border: 1px solid #1E293B;
  display: flex;
  flex-direction: column;
}

.player-topbar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 18px;
  background-color: rgba(2, 6, 23, 0.7);
  color: #F8FAFC;
  font-size: 12.5px;
  font-weight: 600;
}

.yt-badge {
  background-color: #E11D48;
  color: #FFFFFF;
  padding: 1px 5px;
  border-radius: 3px;
  font-size: 10px;
  font-weight: 800;
  margin-right: 6px;
}

.player-status {
  color: #38BDF8;
  font-size: 11.5px;
}

.player-screen {
  height: 270px;
  background: linear-gradient(135deg, #1E1B4B 0%, #0F172A 50%, #0369A1 100%);
  position: relative;
  display: flex;
  align-items: flex-end;
  justify-content: center;
  padding-bottom: 24px;
}

.screen-watermark {
  position: absolute;
  top: 14px;
  right: 18px;
  font-size: 10.5px;
  color: rgba(255, 255, 255, 0.4);
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

.subtitle-box {
  background: rgba(0, 0, 0, 0.85);
  padding: 8px 18px;
  border-radius: 6px;
  backdrop-filter: blur(4px);
  max-width: 90%;
}

.subtitle-text {
  color: #FFFFFF;
  font-size: 18px;
  font-weight: 600;
  line-height: 1.4;
  text-align: center;
}

.subz-word {
  color: var(--accent-amber);
  border-bottom: 2.5px solid var(--accent-amber);
  cursor: pointer;
  padding: 0 2px;
  transition: all 0.15s ease;
}

.subz-word:hover {
  background-color: var(--accent-amber-bg);
  border-radius: 2px;
}

.player-controls {
  background-color: rgba(2, 6, 23, 0.9);
  padding: 10px 18px;
}

.playback-bar {
  height: 4px;
  background: #334155;
  border-radius: 2px;
  margin-bottom: 8px;
  overflow: hidden;
}

.playback-fill {
  width: 25%;
  height: 100%;
  background: #E11D48;
}

.controls-row {
  display: flex;
  align-items: center;
  gap: 14px;
  color: #94A3B8;
  font-size: 12px;
}

.control-btn {
  color: #FFFFFF;
  cursor: pointer;
  font-weight: 700;
}

.control-pill {
  margin-left: auto;
  background-color: rgba(255, 255, 255, 0.15);
  color: #FFFFFF;
  padding: 2px 7px;
  border-radius: 4px;
  font-size: 11px;
}

/* Interactive Card Replica */
.interactive-card {
  width: 340px;
  background-color: #FFFFFF;
  border: 1px solid var(--border-light);
  border-radius: 14px;
  box-shadow: var(--shadow-xl);
  padding: 18px;
  text-align: left;
  animation: cardFloat 0.2s ease;
}

.card-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: 8px;
}

.card-title-group {
  display: flex;
  align-items: center;
  gap: 7px;
}

.card-word {
  font-size: 20px;
  font-weight: 800;
  color: var(--text-main);
  letter-spacing: -0.02em;
}

.card-pos {
  font-size: 11px;
  font-style: italic;
  font-weight: 600;
  color: var(--text-muted);
  background: #F1F5F9;
  padding: 2px 6px;
  border-radius: 4px;
}

.card-level {
  font-size: 10.5px;
  font-weight: 700;
  color: #2563EB;
  background: #EFF6FF;
  padding: 2px 6px;
  border-radius: 4px;
}

.card-btn-save {
  font-size: 12px;
  font-weight: 700;
  color: var(--primary-blue);
  background: #F0F7FF;
  border: 1px solid #BFDBFE;
  padding: 3px 10px;
  border-radius: 6px;
  cursor: pointer;
}

.card-audio-row {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-bottom: 10px;
}

.card-phonetic {
  font-size: 12px;
  color: var(--text-muted);
  font-family: 'JetBrains Mono', monospace;
}

.audio-pill {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  background: #F8FAFC;
  border: 1px solid var(--border-light);
  padding: 3px 9px;
  border-radius: 12px;
  font-size: 11px;
  font-weight: 600;
  color: #334155;
  cursor: pointer;
  transition: all 0.15s ease;
}

.audio-pill:hover {
  background: #FFFFFF;
  border-color: #94A3B8;
  color: var(--text-main);
}

.card-definition {
  font-size: 13.5px;
  font-weight: 500;
  color: #1E293B;
  margin-bottom: 12px;
  line-height: 1.45;
}

.card-context {
  background: #F8FAFC;
  border-left: 3px solid var(--primary-blue);
  padding: 8px 10px;
  border-radius: 0 6px 6px 0;
  font-size: 11.5px;
  color: var(--text-muted);
  margin-bottom: 14px;
  line-height: 1.4;
}

.card-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-top: 1px solid var(--border-subtle);
  padding-top: 10px;
}

.btn-replay {
  background: #FFFFFF;
  border: 1px solid #CBD5E1;
  padding: 6px 11px;
  border-radius: 8px;
  font-size: 11.5px;
  font-weight: 600;
  color: #334155;
  cursor: pointer;
}

.btn-ghost {
  font-size: 11px;
  color: var(--text-subtle);
  text-decoration: underline;
  cursor: pointer;
}

.btn-resume {
  background: var(--primary-blue);
  color: #FFFFFF;
  border: none;
  padding: 7px 15px;
  border-radius: 8px;
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
}

/* Feature Grid */
.features {
  padding: 80px 0;
  background-color: var(--bg-subtle);
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 24px;
}

.feature-card {
  background: #FFFFFF;
  border: 1px solid var(--border-light);
  border-radius: 14px;
  padding: 28px;
  box-shadow: var(--shadow-sm);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.feature-card:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-md);
}

.feature-icon {
  width: 44px;
  height: 44px;
  border-radius: 10px;
  background-color: #EFF6FF;
  color: var(--primary-blue);
  display: inline-flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
}

.feature-icon svg {
  display: block;
}

.feature-card h3 {
  font-size: 19px;
  margin-bottom: 10px;
}

.feature-card p {
  color: var(--text-muted);
  font-size: 14px;
  line-height: 1.55;
}

/* Steps Section */
.steps-section {
  padding: 80px 0;
}

.steps-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
}

.step-card {
  background: #FFFFFF;
  border: 1px solid var(--border-light);
  border-radius: 14px;
  padding: 30px;
  position: relative;
}

.step-number {
  font-size: 32px;
  font-weight: 800;
  color: #E2E8F0;
  margin-bottom: 14px;
  letter-spacing: -0.04em;
}

.step-card h3 {
  font-size: 20px;
  margin-bottom: 8px;
}

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

/* Privacy Section */
.privacy-section {
  padding: 40px 0 80px;
}

.privacy-box {
  background: #F8FAFC;
  border: 1px solid var(--border-light);
  border-radius: 16px;
  padding: 48px;
  text-align: center;
  max-width: 820px;
}

.privacy-badge {
  display: inline-block;
  font-size: 12px;
  font-weight: 700;
  color: #059669;
  background: #ECFDF5;
  border: 1px solid #A7F3D0;
  padding: 4px 12px;
  border-radius: 20px;
  margin-bottom: 16px;
}

.privacy-box h2 {
  font-size: 28px;
  margin-bottom: 14px;
}

.privacy-box p {
  font-size: 15.5px;
  color: var(--text-muted);
  line-height: 1.6;
  margin-bottom: 24px;
}

.privacy-checks {
  display: flex;
  justify-content: center;
  gap: 24px;
  font-weight: 700;
  font-size: 13.5px;
  color: #334155;
  flex-wrap: wrap;
}

/* CTA Banner */
.cta-banner {
  padding: 70px 0;
  background: radial-gradient(circle at 50% 50%, #006CF2 0%, #0284C7 100%);
  color: #FFFFFF;
  text-align: center;
}

.cta-banner h2 {
  color: #FFFFFF;
  font-size: 36px;
  margin-bottom: 12px;
}

.cta-banner p {
  color: rgba(255, 255, 255, 0.9);
  font-size: 18px;
  margin-bottom: 28px;
}

.cta-banner-buttons {
  display: flex;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
}

.cta-banner .btn-primary {
  background-color: #FFFFFF;
  color: var(--primary-blue);
  border-color: #FFFFFF;
}

.cta-banner .btn-primary:hover {
  background-color: #F8FAFC;
  transform: translateY(-1px);
}

.cta-banner .btn-secondary {
  background-color: rgba(255, 255, 255, 0.15);
  color: #FFFFFF;
  border-color: rgba(255, 255, 255, 0.3);
}

.cta-banner .btn-secondary:hover {
  background-color: rgba(255, 255, 255, 0.25);
  transform: translateY(-1px);
}

/* Footer */
.footer {
  padding: 50px 0 40px;
  background-color: var(--bg-main);
  border-top: 1px solid var(--border-subtle);
}

.footer-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 24px;
}

.footer-tagline {
  font-size: 13px;
  color: var(--text-subtle);
  margin-top: 6px;
}

.footer-attribution {
  text-align: right;
  font-size: 13px;
  color: var(--text-muted);
}

.surfboard-link {
  color: var(--text-main);
  font-weight: 700;
  text-decoration: none;
}

.surfboard-link:hover {
  color: var(--primary-blue);
}

.copyright {
  font-size: 11.5px;
  color: var(--text-subtle);
  margin-top: 4px;
}

/* Mobile Responsiveness */
@media (max-width: 768px) {
  .hero-title { font-size: 38px; }
  .nav-links { display: none; }
  .player-mockup { width: 100%; }
  .interactive-card { width: 100%; }
  .footer-container { flex-direction: column; text-align: center; }
  .footer-attribution { text-align: center; }
}