/* ============================================================
   Piano Keyboards — Shared Stylesheet
   ============================================================ */

:root {
  --bg: #0a0a1a;
  --bg-elev: #11132a;
  --surface: rgba(255, 255, 255, 0.04);
  --surface-hover: rgba(255, 255, 255, 0.07);
  --border: rgba(255, 255, 255, 0.08);
  --text: #ffffff;
  --text-muted: rgba(255, 255, 255, 0.65);
  --text-dim: rgba(255, 255, 255, 0.4);
  --accent: #39ff14;
  --accent-dim: #00cc66;
  --accent-grad: linear-gradient(135deg, #39ff14 0%, #00cc66 100%);
  --shadow: 0 12px 40px rgba(0, 0, 0, 0.5);
  --radius: 16px;
  --radius-sm: 10px;
}

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

html {
  scroll-behavior: smooth;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "Segoe UI",
    Roboto, "Helvetica Neue", Arial, sans-serif;
  background:
    radial-gradient(ellipse 80% 60% at 50% -20%, rgba(57, 255, 20, 0.15), transparent 50%),
    radial-gradient(ellipse 60% 50% at 80% 30%, rgba(120, 80, 200, 0.12), transparent 60%),
    var(--bg);
  color: var(--text);
  line-height: 1.6;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

/* ===== Header ===== */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  background: rgba(10, 10, 26, 0.7);
  border-bottom: 1px solid var(--border);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--text);
  font-weight: 700;
  font-size: 1.15rem;
  letter-spacing: -0.01em;
}

.brand-icon {
  width: 34px;
  height: 34px;
  border-radius: 9px;
  background: var(--accent-grad);
  display: grid;
  place-items: center;
  font-size: 18px;
  box-shadow: 0 4px 12px rgba(57, 255, 20, 0.3);
}

.nav-links {
  display: flex;
  gap: 32px;
  list-style: none;
}

.nav-links a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: 500;
  transition: color 0.2s;
}

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

.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 11px 22px;
  border-radius: 999px;
  border: none;
  font-family: inherit;
  font-size: 0.95rem;
  font-weight: 600;
  text-decoration: none;
  cursor: pointer;
  transition: transform 0.15s, box-shadow 0.2s;
}

.btn-primary {
  background: var(--accent-grad);
  color: #001a08;
  box-shadow: 0 6px 20px rgba(57, 255, 20, 0.3);
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 10px 28px rgba(57, 255, 20, 0.45);
}

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

.btn-ghost:hover {
  background: var(--surface-hover);
}

/* ===== Hero ===== */
.hero {
  padding: 100px 0 80px;
  text-align: center;
}

.eyebrow {
  display: inline-block;
  padding: 6px 14px;
  border-radius: 999px;
  background: var(--surface);
  border: 1px solid var(--border);
  font-size: 0.82rem;
  color: var(--accent);
  font-weight: 600;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  margin-bottom: 24px;
}

.hero h1 {
  font-size: clamp(2.2rem, 5.5vw, 4rem);
  font-weight: 800;
  line-height: 1.05;
  letter-spacing: -0.03em;
  margin-bottom: 22px;
  background: linear-gradient(180deg, #ffffff 0%, #c0c0d4 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero h1 .accent {
  background: var(--accent-grad);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero p.lead {
  font-size: clamp(1.05rem, 1.8vw, 1.25rem);
  color: var(--text-muted);
  max-width: 640px;
  margin: 0 auto 38px;
}

.hero-cta {
  display: flex;
  justify-content: center;
  gap: 12px;
  flex-wrap: wrap;
}

/* ===== Sections ===== */
section {
  padding: 80px 0;
}

.section-head {
  text-align: center;
  max-width: 680px;
  margin: 0 auto 56px;
}

.section-head h2 {
  font-size: clamp(1.8rem, 3.5vw, 2.6rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 14px;
}

.section-head p {
  color: var(--text-muted);
  font-size: 1.05rem;
}

/* ===== Steps ===== */
.steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 20px;
}

.step {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 28px;
  position: relative;
  transition: transform 0.2s, background 0.2s;
}

.step:hover {
  transform: translateY(-4px);
  background: var(--surface-hover);
}

.step-num {
  position: absolute;
  top: 24px;
  right: 28px;
  font-size: 3rem;
  font-weight: 800;
  color: var(--accent);
  opacity: 0.3;
  line-height: 1;
}

.step h3 {
  font-size: 1.25rem;
  margin-bottom: 10px;
  letter-spacing: -0.01em;
}

.step p {
  color: var(--text-muted);
  font-size: 0.97rem;
}

/* ===== Features ===== */
.features {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
}

.feature {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 26px;
  transition: transform 0.2s, background 0.2s, border-color 0.2s;
}

.feature:hover {
  transform: translateY(-4px);
  background: var(--surface-hover);
  border-color: rgba(57, 255, 20, 0.25);
}

.feature-icon {
  width: 48px;
  height: 48px;
  border-radius: 12px;
  background: rgba(57, 255, 20, 0.12);
  border: 1px solid rgba(57, 255, 20, 0.25);
  display: grid;
  place-items: center;
  font-size: 22px;
  margin-bottom: 18px;
}

.feature h3 {
  font-size: 1.15rem;
  margin-bottom: 8px;
  letter-spacing: -0.01em;
}

.feature p {
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* ===== Showcase ===== */
.showcase {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: 24px;
}

.showcase-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 28px 32px;
  display: flex;
  flex-direction: column;
  gap: 22px;
  transition: transform 0.25s, border-color 0.25s, background 0.25s;
}

.showcase-card:hover {
  transform: translateY(-4px);
  background: var(--surface-hover);
  border-color: rgba(57, 255, 20, 0.25);
}

.showcase-card h3 {
  font-size: 1.4rem;
  letter-spacing: -0.01em;
}

.showcase-card p {
  color: var(--text-muted);
  font-size: 1rem;
}

.showcase-visual {
  background: linear-gradient(180deg, #060a06 0%, #0a0f0a 100%);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 22px;
  height: 200px;
  display: grid;
  place-items: center;
  position: relative;
  overflow: hidden;
}

.showcase-visual::after {
  content: "";
  position: absolute;
  inset: 0;
  background: radial-gradient(ellipse at center top, rgba(57, 255, 20, 0.08), transparent 70%);
  pointer-events: none;
}

/* Piano keyboard mockup */
.keyboard {
  position: relative;
  width: 100%;
  max-width: 320px;
  height: 130px;
  display: flex;
  border-radius: 6px;
  overflow: hidden;
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.6), 0 0 0 1px rgba(255, 255, 255, 0.05);
}

.key-white {
  flex: 1;
  background: linear-gradient(180deg, #fafafa 0%, #d8d8d8 100%);
  border-right: 1px solid #999;
  position: relative;
}

.key-white:last-child {
  border-right: none;
}

.key-white.lit {
  background: linear-gradient(180deg, #88ff66 0%, #39ff14 80%, #0a8a1a 100%);
  box-shadow:
    inset 0 -20px 30px rgba(0, 180, 60, 0.55),
    inset 0 4px 8px rgba(255, 255, 255, 0.3);
}

.key-black {
  position: absolute;
  top: 0;
  width: 9%;
  height: 62%;
  background: linear-gradient(180deg, #2a2a2a 0%, #000 100%);
  border-radius: 0 0 4px 4px;
  box-shadow:
    0 4px 6px rgba(0, 0, 0, 0.6),
    inset 0 2px 2px rgba(255, 255, 255, 0.1);
  z-index: 2;
}

/* Piano roll mockup */
.piano-roll {
  position: relative;
  width: 100%;
  max-width: 320px;
  height: 130px;
  background:
    repeating-linear-gradient(
      0deg,
      transparent 0,
      transparent calc(100% / 8 - 1px),
      rgba(255, 255, 255, 0.06) calc(100% / 8 - 1px),
      rgba(255, 255, 255, 0.06) calc(100% / 8)
    ),
    repeating-linear-gradient(
      90deg,
      transparent 0,
      transparent calc(100% / 12 - 1px),
      rgba(255, 255, 255, 0.04) calc(100% / 12 - 1px),
      rgba(255, 255, 255, 0.04) calc(100% / 12)
    ),
    #050a05;
  border-radius: 6px;
  overflow: hidden;
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.6), 0 0 0 1px rgba(255, 255, 255, 0.05);
}

.note {
  position: absolute;
  height: calc(100% / 8 - 2px);
  background: linear-gradient(90deg, #39ff14, #00cc66);
  border-radius: 3px;
  box-shadow:
    0 0 10px rgba(57, 255, 20, 0.55),
    inset 0 1px 0 rgba(255, 255, 255, 0.4);
}

.playhead {
  position: absolute;
  top: 0;
  bottom: 0;
  width: 2px;
  background: rgba(255, 255, 255, 0.65);
  box-shadow: 0 0 8px rgba(255, 255, 255, 0.7);
  z-index: 3;
}

/* ===== CTA banner ===== */
.cta-banner {
  background:
    radial-gradient(ellipse at top left, rgba(57, 255, 20, 0.18), transparent 60%),
    var(--surface);
  border: 1px solid var(--border);
  border-radius: 24px;
  padding: 56px 40px;
  text-align: center;
}

.cta-banner h2 {
  font-size: clamp(1.6rem, 3vw, 2.2rem);
  margin-bottom: 14px;
  letter-spacing: -0.02em;
}

.cta-banner p {
  color: var(--text-muted);
  margin-bottom: 28px;
  max-width: 500px;
  margin-left: auto;
  margin-right: auto;
}

/* ===== Footer ===== */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 48px 0 32px;
  margin-top: 60px;
}

.footer-grid {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 40px;
  flex-wrap: wrap;
  margin-bottom: 32px;
}

.footer-brand {
  max-width: 320px;
}

.footer-brand p {
  color: var(--text-muted);
  font-size: 0.92rem;
  margin-top: 12px;
}

.footer-links {
  display: flex;
  gap: 48px;
  flex-wrap: wrap;
}

.footer-col h4 {
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-dim);
  margin-bottom: 14px;
  font-weight: 600;
}

.footer-col ul {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-col a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.95rem;
  transition: color 0.2s;
}

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

.footer-bottom {
  border-top: 1px solid var(--border);
  padding-top: 24px;
  display: flex;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
  color: var(--text-dim);
  font-size: 0.88rem;
}

/* ============================================================
   Privacy Policy Page
   ============================================================ */

.doc-hero {
  padding: 60px 0 30px;
  text-align: center;
  border-bottom: 1px solid var(--border);
}

.doc-hero h1 {
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 800;
  letter-spacing: -0.02em;
  margin-bottom: 12px;
}

.doc-hero .meta {
  color: var(--text-muted);
  font-size: 0.95rem;
}

.doc-layout {
  display: grid;
  grid-template-columns: 260px 1fr;
  gap: 48px;
  padding: 56px 0 80px;
}

.toc {
  position: sticky;
  top: 90px;
  align-self: start;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px 20px;
  max-height: calc(100vh - 110px);
  overflow-y: auto;
}

.toc h4 {
  font-size: 0.8rem;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-dim);
  margin-bottom: 14px;
  font-weight: 700;
}

.toc ol {
  list-style: none;
  counter-reset: toc;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.toc ol li {
  counter-increment: toc;
}

.toc ol li a {
  display: block;
  padding: 7px 10px;
  border-radius: 8px;
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.9rem;
  transition: background 0.15s, color 0.15s;
}

.toc ol li a::before {
  content: counter(toc) ". ";
  color: var(--text-dim);
  margin-right: 4px;
}

.toc ol li a:hover {
  background: var(--surface-hover);
  color: var(--text);
}

.doc-body {
  max-width: 760px;
  font-size: 1rem;
  line-height: 1.75;
}

.doc-body h2 {
  font-size: 1.55rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin: 48px 0 16px;
  padding-top: 16px;
  scroll-margin-top: 90px;
}

.doc-body h2:first-child {
  margin-top: 0;
}

.doc-body h3 {
  font-size: 1.1rem;
  margin: 24px 0 10px;
  color: var(--accent);
  font-weight: 600;
}

.doc-body p {
  color: var(--text-muted);
  margin-bottom: 14px;
}

.doc-body p strong {
  color: var(--text);
  font-weight: 600;
}

.doc-body ul {
  margin: 8px 0 16px 22px;
  color: var(--text-muted);
}

.doc-body ul li {
  margin-bottom: 6px;
}

.doc-body a {
  color: var(--accent);
  text-decoration: none;
  border-bottom: 1px solid rgba(57, 255, 20, 0.3);
  transition: border-color 0.2s;
}

.doc-body a:hover {
  border-color: var(--accent);
}

.callout {
  background: rgba(57, 255, 20, 0.07);
  border: 1px solid rgba(57, 255, 20, 0.2);
  border-radius: var(--radius-sm);
  padding: 16px 18px;
  margin: 18px 0;
}

.callout p {
  color: var(--text);
  margin: 0;
  font-size: 0.95rem;
}

/* ===== 404 ===== */
.error-page {
  min-height: 70vh;
  display: grid;
  place-items: center;
  text-align: center;
  padding: 60px 24px;
}

.error-code {
  font-size: clamp(5rem, 14vw, 9rem);
  font-weight: 800;
  background: var(--accent-grad);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
  line-height: 1;
  letter-spacing: -0.04em;
}

.error-page p {
  color: var(--text-muted);
  margin: 16px 0 28px;
  font-size: 1.1rem;
}

/* ===== Responsive ===== */
@media (max-width: 860px) {
  .nav-links {
    display: none;
  }
  .doc-layout {
    grid-template-columns: 1fr;
    gap: 24px;
  }
  .toc {
    position: static;
    max-height: none;
  }
  .footer-grid {
    flex-direction: column;
  }
  section {
    padding: 60px 0;
  }
  .hero {
    padding: 70px 0 50px;
  }
}