/* ==========================================================================
   Vibe Coding Workshop — Apple-inspired GitHub Pages
   ========================================================================== */

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

:root {
  --text:        #1d1d1f;
  --text-muted:  #86868b;
  --text-light:  #f5f5f7;
  --bg:          #ffffff;
  --bg-alt:      #f5f5f7;
  --bg-dark:     #000000;
  --accent:      #0071e3;
  --accent-hover:#0077ed;
  --border:      #d2d2d7;
  --radius:      14px;
  --radius-sm:   10px;
  --max-w:       980px;
  --font: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text",
          "Helvetica Neue", "Segoe UI", Roboto, sans-serif;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.5;
  overflow-x: hidden;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; display: block; }

.container {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
}

/* ---------- Nav ---------- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(255,255,255,0.72);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 0.5px solid rgba(0,0,0,0.08);
}

.nav-inner {
  max-width: var(--max-w);
  margin: 0 auto;
  padding: 0 24px;
  height: 48px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  font-size: 15px;
  font-weight: 600;
  color: var(--text);
  letter-spacing: -0.01em;
}
.nav-logo:hover { text-decoration: none; }

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

.nav-links a {
  font-size: 13px;
  color: var(--text);
  opacity: 0.8;
  transition: opacity 0.2s;
}
.nav-links a:hover { opacity: 1; text-decoration: none; }

.nav-cta {
  font-weight: 500;
  color: var(--accent) !important;
  opacity: 1 !important;
}

/* ---------- Buttons ---------- */
.btn {
  display: inline-block;
  padding: 12px 24px;
  border-radius: 980px;
  font-size: 17px;
  font-weight: 400;
  letter-spacing: -0.01em;
  transition: all 0.2s;
  cursor: pointer;
  border: none;
}
.btn:hover { text-decoration: none; }

.btn-primary {
  background: var(--accent);
  color: #fff;
}
.btn-primary:hover { background: var(--accent-hover); }

.btn-ghost {
  background: transparent;
  color: var(--accent);
}
.btn-ghost:hover { text-decoration: underline; }

.btn-lg {
  padding: 16px 32px;
  font-size: 19px;
}

/* ---------- Sections ---------- */
.section {
  padding: 100px 0;
  text-align: center;
}

.section-alt { background: var(--bg-alt); }

.section-dark {
  background: var(--bg-dark);
  color: var(--text-light);
}

.section-eyebrow {
  font-size: 15px;
  font-weight: 600;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin-bottom: 8px;
}
.section-dark .section-eyebrow { color: #6cb4ff; }

.section-title {
  font-size: 48px;
  font-weight: 700;
  letter-spacing: -0.025em;
  line-height: 1.1;
  margin-bottom: 16px;
}

.section-desc {
  font-size: 19px;
  color: var(--text-muted);
  line-height: 1.5;
  max-width: 600px;
  margin: 0 auto 48px;
}
.section-dark .section-desc { color: #a1a1a6; }

/* ---------- Hero ---------- */
.hero {
  padding: 160px 0 100px;
  text-align: center;
  background: linear-gradient(180deg, #fbfbfd 0%, #fff 100%);
}

.hero-eyebrow {
  font-size: 14px;
  font-weight: 500;
  color: var(--text-muted);
  letter-spacing: 0.02em;
  margin-bottom: 16px;
}

.hero-title {
  font-size: 56px;
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.08;
  margin-bottom: 20px;
  background: linear-gradient(135deg, var(--text) 0%, #434343 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.hero-subtitle {
  font-size: 21px;
  color: var(--text-muted);
  line-height: 1.5;
  max-width: 600px;
  margin: 0 auto 36px;
}
.hero-subtitle strong {
  color: var(--text);
  -webkit-text-fill-color: var(--text);
}

.hero-actions {
  display: flex;
  justify-content: center;
  gap: 16px;
}

/* ---------- Card Demo ---------- */
.card-demo {
  display: flex;
  justify-content: center;
  margin: 56px 0 40px;
}

.card-mock {
  background: #fff;
  border-radius: var(--radius);
  padding: 36px 40px;
  width: 440px;
  text-align: left;
  box-shadow:
    0 0 0 0.5px rgba(255,255,255,0.1),
    0 20px 60px rgba(0,0,0,0.5);
}

.card-mock-context {
  font-size: 13px;
  color: #888;
  line-height: 1.7;
  margin: 2px 0;
}

.card-mock-highlight {
  display: flex;
  gap: 14px;
  margin: 14px 0;
}

.card-mock-bar {
  flex-shrink: 0;
  width: 4px;
  border-radius: 2px;
  background: linear-gradient(180deg, #0071e3, #5e5ce6);
}

.card-mock-text {
  font-size: 17px;
  font-weight: 600;
  color: #1d1d1f;
  line-height: 1.65;
}

.card-mock-divider {
  border: none;
  border-top: 1px solid #e8e8e8;
  margin: 20px 0 16px;
}

.card-mock-footer {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.card-mock-source {
  font-size: 13px;
  color: #555;
  font-weight: 500;
}

.card-mock-hint {
  font-size: 11px;
  color: #aaa;
  margin-top: 2px;
}

.card-mock-qr {
  opacity: 0.6;
}

/* Feature chips */
.features-strip {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 10px;
}

.feature-chip {
  padding: 8px 18px;
  border-radius: 980px;
  font-size: 14px;
  font-weight: 500;
  background: rgba(255,255,255,0.08);
  color: #ccc;
  border: 1px solid rgba(255,255,255,0.1);
}

/* ---------- Reasons grid ---------- */
.reasons-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
  max-width: 720px;
  margin: 0 auto;
  text-align: left;
}

.reason-card {
  padding: 32px 28px;
  background: var(--bg-alt);
  border-radius: var(--radius);
  border: 1px solid var(--border);
  transition: transform 0.2s, box-shadow 0.2s;
}
.reason-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0,0,0,0.06);
}

.reason-icon {
  font-size: 28px;
  margin-bottom: 12px;
}

.reason-card h3 {
  font-size: 17px;
  font-weight: 600;
  margin-bottom: 6px;
  letter-spacing: -0.01em;
}

.reason-card p {
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.5;
}

/* ---------- Timeline ---------- */
.timeline {
  max-width: 560px;
  margin: 0 auto;
  text-align: left;
  position: relative;
}

.timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: var(--border);
  border-radius: 1px;
}

.timeline-item {
  position: relative;
  padding-left: 36px;
  padding-bottom: 32px;
}
.timeline-item:last-child { padding-bottom: 0; }

.timeline-dot {
  position: absolute;
  left: 0;
  top: 6px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--bg-alt);
  border: 2px solid var(--border);
  transition: all 0.2s;
}

.timeline-item-highlight .timeline-dot {
  background: var(--accent);
  border-color: var(--accent);
  box-shadow: 0 0 0 4px rgba(0,113,227,0.15);
}

.timeline-time {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-muted);
  letter-spacing: 0.02em;
  margin-bottom: 2px;
}

.timeline-content h3 {
  font-size: 17px;
  font-weight: 600;
  letter-spacing: -0.01em;
  margin-bottom: 4px;
}
.timeline-item-highlight .timeline-content h3 { color: var(--accent); }

.timeline-content p {
  font-size: 14px;
  color: var(--text-muted);
  line-height: 1.45;
}

/* ---------- Skills grid ---------- */
.skills-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  max-width: 720px;
  margin: 0 auto;
}

.skill-card {
  padding: 28px 20px;
  background: var(--bg-alt);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
  text-align: center;
  transition: transform 0.2s;
}
.skill-card:hover { transform: translateY(-2px); }

.skill-icon { font-size: 28px; margin-bottom: 10px; }

.skill-name {
  font-size: 15px;
  font-weight: 600;
  margin-bottom: 4px;
  letter-spacing: -0.01em;
}

.skill-desc {
  font-size: 13px;
  color: var(--text-muted);
}

/* ---------- Prerequisites ---------- */
.prereqs-list {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
  margin-bottom: 24px;
}

.prereq-item {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 19px;
  color: var(--text-light);
}

.prereq-check { font-size: 20px; }

.prereqs-note {
  font-size: 15px;
  color: #86868b;
  font-style: italic;
}

/* ---------- Quote ---------- */
.section-quote {
  padding: 100px 0;
  background: var(--bg-alt);
}

.quote {
  font-size: 32px;
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1.35;
  color: var(--text);
  max-width: 700px;
  margin: 0 auto;
  text-align: center;
}

/* ---------- CTA ---------- */
.section-cta {
  padding: 120px 0;
  background: linear-gradient(180deg, #fff 0%, #f5f5f7 100%);
}

.cta-title {
  font-size: 48px;
  font-weight: 700;
  letter-spacing: -0.025em;
  margin-bottom: 12px;
}

.cta-desc {
  font-size: 19px;
  color: var(--text-muted);
  margin-bottom: 32px;
}

/* ---------- Footer ---------- */
.footer {
  padding: 32px 0;
  text-align: center;
  border-top: 1px solid var(--border);
  font-size: 13px;
  color: var(--text-muted);
}

.footer-sub {
  margin-top: 6px;
}

.footer-sub a {
  color: var(--text-muted);
}
.footer-sub a:hover { color: var(--accent); }

/* ---------- Responsive ---------- */
@media (max-width: 768px) {
  .hero { padding: 120px 0 72px; }

  .hero-title { font-size: 36px; }
  .hero-subtitle { font-size: 17px; }

  .section { padding: 72px 0; }
  .section-title { font-size: 32px; }
  .section-desc { font-size: 17px; }

  .nav-links a:not(.nav-cta) { display: none; }

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

  .card-mock { width: 100%; padding: 28px; }

  .quote { font-size: 24px; }
  .cta-title { font-size: 32px; }

  .btn-lg { padding: 14px 28px; font-size: 17px; }
}

@media (max-width: 480px) {
  .skills-grid { grid-template-columns: 1fr; }
  .hero-title { font-size: 30px; }
  .hero-actions { flex-direction: column; align-items: center; }
  .prereq-item { font-size: 17px; }
}