/* Tech Interview Practice — cyber-green dark theme */

.cyber-green,
:root {
  --bg-primary: rgb(12 13 15);
  --bg-primary-10: rgba(12, 13, 15, 0.1);
  --bg-secondary: rgb(24 25 28);
  --bg-card: rgb(16 17 20);
  --text-primary: rgb(242 244 245);
  --text-secondary: rgb(150 155 160);
  --text-muted: rgb(105 110 118);
  --border: rgb(42 44 48);
  --accent: rgb(52 199 140);
  --accent-5: rgba(52, 199, 140, 0.05);
  --accent-10: rgba(52, 199, 140, 0.1);
  --accent-20: rgba(52, 199, 140, 0.2);
  --accent-30: rgba(52, 199, 140, 0.3);
  --accent-40: rgba(52, 199, 140, 0.4);
  --accent-50: rgba(52, 199, 140, 0.5);
  --accent-60: rgba(52, 199, 140, 0.6);
  --accent-70: rgba(52, 199, 140, 0.7);
  --accent-80: rgba(52, 199, 140, 0.8);
  --accent-90: rgba(52, 199, 140, 0.9);
  --accent-muted: var(--accent-60);
  --chart-1: rgb(52 199 140);
  --chart-2: rgb(100 180 255);
  --chart-3: rgb(165 201 50);
  --chart-4: rgb(245 195 100);
  --chart-5: rgb(255 105 115);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.35);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 20px 48px rgba(0, 0, 0, 0.5);
  --max-width: 1120px;
  --font-sans: 'Space Grotesk', system-ui, -apple-system, sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, monospace;
}

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  scrollbar-gutter: stable;
}

body {
  font-family: var(--font-sans);
  color: var(--text-primary);
  background: var(--bg-primary);
  line-height: 1.6;
  overflow-x: hidden;
}

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

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

/* ─── NAVIGATION ─── */

.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  padding-top: env(safe-area-inset-top, 0px);
  background: rgba(12, 13, 15, 0.82);
  backdrop-filter: blur(20px) saturate(160%);
  -webkit-backdrop-filter: blur(20px) saturate(160%);
  border-bottom: 1px solid rgba(42, 44, 48, 0.7);
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0);
  transition: box-shadow 0.3s, border-color 0.3s;
}

.nav.scrolled {
  box-shadow: var(--shadow-sm);
  border-bottom-color: var(--border);
}

.nav-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 1.5rem;
  height: 64px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  text-decoration: none;
  color: var(--text-primary);
}

.nav-logo {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
}

.nav-name {
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.nav-name-short {
  display: none;
}

.nav-cta {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  padding: 0.5rem 1.25rem;
  font-family: inherit;
  font-size: 0.875rem;
  font-weight: 600;
  color: var(--bg-primary);
  background: var(--accent);
  border: none;
  border-radius: 100px;
  cursor: pointer;
  text-decoration: none;
  transition: transform 0.2s, box-shadow 0.2s, background 0.2s;
}

.nav-cta:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 20px var(--accent-40);
  background: var(--accent-90);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

/* ─── SHARED ─── */

.section {
  padding: 5rem 1.5rem;
}

.section-alt {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.section-inner {
  max-width: var(--max-width);
  margin: 0 auto;
}

.section-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  padding: 0.375rem 0.875rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--accent);
  background: var(--accent-10);
  border: 1px solid var(--accent-20);
  border-radius: 100px;
  margin-bottom: 1rem;
  letter-spacing: 0.02em;
}

.section-title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.2;
  color: var(--text-primary);
  margin-bottom: 0.75rem;
}

.section-subtitle {
  font-size: clamp(1rem, 2vw, 1.125rem);
  color: var(--text-secondary);
  line-height: 1.65;
  max-width: 560px;
}

.section-header {
  text-align: center;
  margin-bottom: 3.5rem;
}

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

.mono-label {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  color: var(--text-muted);
}

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

/* ─── PHONE MOCKUP ─── */

.phone-mockup {
  --mockup-scale: 1;
  width: 260px;
  aspect-ratio: 9 / 19.5;
  background: var(--bg-card);
  border: 3px solid var(--border);
  border-radius: 36px;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
  isolation: isolate;
  box-shadow: var(--shadow-lg);
  flex-shrink: 0;
}

.phone-mockup::before {
  content: '';
  position: absolute;
  top: calc(12px * var(--mockup-scale));
  left: 50%;
  transform: translateX(-50%);
  width: calc(80px * var(--mockup-scale));
  height: calc(16px * var(--mockup-scale));
  background: var(--border);
  border-radius: 100px;
  z-index: 2;
}

.phone-mockup img {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  border-radius: 33px;
  display: block;
}

.phone-mockup-lg {
  width: 300px;
  --mockup-scale: calc(300 / 260);
}

.phone-glow {
  position: absolute;
  width: 300px;
  height: 300px;
  border-radius: 50%;
  z-index: 0;
}

.glow-green {
  background: radial-gradient(circle, var(--accent-20) 0%, transparent 70%);
}

.glow-blue {
  background: radial-gradient(circle, rgba(100, 180, 255, 0.12) 0%, transparent 70%);
}

/* ─── HERO ─── */

.hero {
  padding: 7rem 1.5rem 4rem;
  overflow: hidden;
  position: relative;
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 60% 50% at 80% 20%, var(--accent-10) 0%, transparent 60%),
    radial-gradient(ellipse 40% 40% at 10% 80%, rgba(100, 180, 255, 0.06) 0%, transparent 60%);
  pointer-events: none;
}

.hero-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3rem;
  align-items: center;
  position: relative;
  z-index: 1;
}

.hero-content { max-width: 520px; }

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.375rem;
  padding: 0.375rem 0.875rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--accent);
  background: var(--accent-10);
  border: 1px solid var(--accent-20);
  border-radius: 100px;
  margin-bottom: 1.5rem;
}

.hero-title {
  font-size: clamp(2.25rem, 5.5vw, 3.25rem);
  font-weight: 700;
  letter-spacing: -0.035em;
  line-height: 1.1;
  margin-bottom: 1.25rem;
}

.hero-desc {
  font-size: 1.0625rem;
  line-height: 1.65;
  color: var(--text-secondary);
  margin-bottom: 2rem;
  max-width: 440px;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-bottom: 2rem;
}

.hero-visual {
  display: flex;
  justify-content: flex-end;
  align-items: center;
  position: relative;
}

.hero-phone-glow {
  position: absolute;
  width: 340px;
  height: 340px;
  background: radial-gradient(circle, var(--accent-20) 0%, transparent 70%);
  border-radius: 50%;
  z-index: 0;
}

.hero-visual .phone-mockup { z-index: 1; }

/* ─── STATS STRIP ─── */

.stats-strip {
  padding: 2.5rem 1.5rem;
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  background: var(--bg-secondary);
}

.stats-grid {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
}

.stat-item {
  text-align: center;
  padding: 1rem;
}

.stat-value {
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 700;
  color: var(--accent);
  letter-spacing: -0.02em;
  margin-bottom: 0.25rem;
}

.stat-label {
  font-size: 0.875rem;
  color: var(--text-secondary);
}

/* ─── SPLIT SECTIONS ─── */

.split {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 4rem;
  align-items: center;
}

.split-reverse { direction: rtl; }
.split-reverse > * { direction: ltr; }

.split-content { max-width: 480px; }

.split-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 1rem;
  margin-top: 1.5rem;
}

.split-list li {
  display: flex;
  gap: 0.75rem;
  align-items: flex-start;
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.55;
}

.split-list-icon {
  flex-shrink: 0;
  width: 24px;
  height: 24px;
  border-radius: 50%;
  background: var(--accent-10);
  border: 1px solid var(--accent-20);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-top: 0.15em;
}

.split-visual {
  display: flex;
  justify-content: center;
  position: relative;
}

.split-visual.split-visual-left { justify-content: flex-start; }
.split-visual.split-visual-right { justify-content: flex-end; }
.split-visual .phone-mockup { z-index: 1; }

.split-dual-phones {
  display: flex;
  gap: 1rem;
  align-items: flex-end;
}

.split-dual-phones .phone-mockup:first-child {
  width: 220px;
  --mockup-scale: calc(220 / 260);
  transform: translateY(1rem);
  opacity: 0.85;
}

.split-dual-phones .phone-mockup:last-child {
  width: 260px;
  --mockup-scale: 1;
}

/* ─── FEATURES GRID ─── */

.features-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: 1.25rem;
}

.feature-card {
  padding: 1.5rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  transition: transform 0.2s, box-shadow 0.2s, border-color 0.2s;
}

.feature-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
  border-color: var(--accent-30);
}

.feature-icon {
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 1rem;
  background: var(--accent-10);
  border: 1px solid var(--accent-20);
  color: var(--accent);
}

.feature-title {
  font-size: 0.9375rem;
  font-weight: 600;
  margin-bottom: 0.375rem;
  letter-spacing: -0.01em;
}

.feature-desc {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.55;
}

/* ─── AUDIENCE ─── */

.audience-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1.5rem;
}

.audience-card {
  padding: 2rem 1.5rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  text-align: center;
  transition: transform 0.2s, border-color 0.2s;
}

.audience-card:hover {
  transform: translateY(-3px);
  border-color: var(--accent-30);
}

.audience-icon {
  width: 48px;
  height: 48px;
  margin: 0 auto 1rem;
  border-radius: var(--radius-md);
  background: var(--accent-10);
  border: 1px solid var(--accent-20);
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--accent);
}

.audience-title {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  letter-spacing: -0.01em;
}

.audience-desc {
  font-size: 0.875rem;
  color: var(--text-secondary);
  line-height: 1.55;
}

/* ─── CTA ─── */

.cta-section {
  padding: 6rem 1.5rem;
  text-align: center;
  position: relative;
  overflow: hidden;
  border-top: 1px solid var(--border);
}

.cta-section::before {
  content: '';
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse 70% 60% at 50% 50%, var(--accent-10) 0%, transparent 70%);
  pointer-events: none;
}

.cta-inner {
  max-width: 650px;
  margin: 0 auto;
  position: relative;
  z-index: 1;
}

.cta-title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.2;
  margin-bottom: 1rem;
}

.cta-desc {
  font-size: 1.0625rem;
  color: var(--text-secondary);
  margin-bottom: 2rem;
  line-height: 1.6;
}

.cta-buttons {
  display: flex;
  justify-content: center;
  gap: 0.75rem;
  flex-wrap: wrap;
}

.store-btn {
  display: inline-block;
  text-decoration: none;
  transition: transform 0.2s, opacity 0.2s;
  line-height: 0;
}

.store-btn:hover {
  transform: translateY(-2px);
  opacity: 0.9;
}

.store-btn img {
  display: block;
  height: 40px;
  width: auto;
}

/* ─── PAGE HERO (FAQ, Support) ─── */

.page-hero {
  padding: calc(3rem + 64px + env(safe-area-inset-top, 0px)) 1.5rem 3rem;
  text-align: center;
  background: var(--bg-secondary);
  border-bottom: 1px solid var(--border);
}

.page-hero-inner {
  max-width: var(--max-width);
  margin: 0 auto;
}

.page-hero .section-badge { margin-bottom: 1rem; }
.page-hero .section-title { margin-bottom: 0.5rem; }

/* ─── FAQ & SUPPORT ─── */

.faq-section {
  padding: 4rem 1.5rem 5rem;
}

body:has(#support) {
  min-height: 100vh;
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
}

body:has(#support) > section#support {
  flex: 1 0 auto;
  display: flex;
  flex-direction: column;
}

body:has(#support) > section#support > .section-inner {
  flex: 1;
}

.faq-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  max-width: 720px;
  margin: 0 auto;
}

.faq-item {
  padding: 1.5rem;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
}

.faq-q {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 0.5rem;
  letter-spacing: -0.01em;
}

.faq-a {
  font-size: 0.9375rem;
  color: var(--text-secondary);
  line-height: 1.6;
}

.support-content {
  max-width: 560px;
  margin: 0 auto;
  font-size: 1rem;
  color: var(--text-secondary);
  line-height: 1.65;
}

.support-content p + p { margin-top: 1rem; }

.support-intro a,
.support-content a {
  color: var(--accent);
  text-decoration: underline;
  text-underline-offset: 2px;
}

/* ─── FOOTER ─── */

.footer {
  padding: 2rem 1.5rem;
  border-top: 1px solid var(--border);
  background: var(--bg-primary);
}

.footer-inner {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
}

.footer-copy {
  font-size: 0.875rem;
  color: var(--text-muted);
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 1.25rem;
}

.footer-links a {
  font-size: 0.875rem;
  color: var(--text-secondary);
  text-decoration: none;
  transition: color 0.2s;
}

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

/* ─── SCROLL REVEAL ─── */

.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in.visible {
  opacity: 1;
  transform: translateY(0);
}

.fade-in-delay-1 { transition-delay: 0.1s; }
.fade-in-delay-2 { transition-delay: 0.2s; }
.fade-in-delay-3 { transition-delay: 0.3s; }

/* ─── RESPONSIVE ─── */

@media (max-width: 960px) {
  .hero-inner,
  .split {
    grid-template-columns: 1fr;
    gap: 2.5rem;
  }

  .split-reverse { direction: ltr; }

  .hero-visual,
  .split-visual.split-visual-left,
  .split-visual.split-visual-right {
    justify-content: center;
  }

  .hero-content { max-width: none; text-align: center; }
  .hero-desc { margin-left: auto; margin-right: auto; }
  .hero-actions { justify-content: center; }

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

  .split-dual-phones {
    justify-content: center;
  }
}

@media (max-width: 640px) {
  .nav-name-full { display: none; }
  .nav-name-short { display: inline; }

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

  .split-dual-phones {
    flex-direction: column;
    align-items: center;
  }

  .split-dual-phones .phone-mockup:first-child {
    transform: none;
    width: 240px;
    --mockup-scale: calc(240 / 260);
  }

  .phone-mockup-lg {
    width: 260px;
    --mockup-scale: 1;
  }
}