/* ============================================================
   FreeStream Web — Apple HIG Craftsmanship + Modern Neumorphic Design System
   ============================================================ */

:root {
  /* Machined Anodized Slate Dark Substrate (#1E2024 — never pure #000000) */
  --bg:               #1E2024;
  --surface:          #23252A;
  --surface-dark:     #181A1E;
  --surface-glass:    rgba(22, 22, 23, 0.72);
  --border:           rgba(255, 255, 255, 0.08);
  --border-inset:     rgba(0, 0, 0, 0.45);
  --specular:         rgba(255, 255, 255, 0.10);
  --accent:           #0071E3;
  --accent-bright:    #2997FF;
  --accent-subtle:    rgba(41, 151, 255, 0.14);
  --led-cyan:         #00E5FF;
  --text:             #F5F5F7;
  --text-muted:       #94A3B8;
  --text-dim:         #64748B;

  /* 135deg Top-Left Directional Light Source */
  --neu-shadow-dark:  rgba(10, 11, 13, 0.78);
  --neu-shadow-light: rgba(42, 45, 52, 0.70);

  /* Typography & Concentric Radii (R_outer = R_inner + Padding) */
  --font-sans:        -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "Inter", system-ui, sans-serif;
  --font-mono:        "SF Mono", ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  --radius-sm:        8px;
  --radius-md:        14px;
  --radius-lg:        24px;
  --radius-xl:        28px;

  /* Motion Curves (Zero Linear) */
  --ease-out-expo:    cubic-bezier(0.16, 1, 0.3, 1);
  --ease-sheet:       cubic-bezier(0.32, 0.72, 0, 1);
}

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

html {
  scroll-behavior: smooth;
}

body {
  background-color: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.6;
  letter-spacing: -0.01em;
  min-height: 100vh;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  font-feature-settings: "kern" 1, "liga" 1, "calt" 1;
}

/* Accessible focus indicator */
:focus-visible {
  outline: 2px solid var(--accent-bright) !important;
  outline-offset: 3px;
  box-shadow: 0 0 0 4px rgba(41, 151, 255, 0.28) !important;
}

/* Screen-reader utility */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

/* ---- Neumorphic Surface Utilities ---- */

.psx-outset {
  background: linear-gradient(145deg, var(--surface), var(--surface-dark));
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow:
    inset 0 1px 0 0 var(--specular),
    8px 8px 16px var(--neu-shadow-dark),
    -8px -8px 16px var(--neu-shadow-light);
}

.psx-inset {
  background-color: var(--surface-dark);
  border: 1px solid var(--border-inset);
  border-radius: var(--radius-md);
  box-shadow:
    inset 4px 4px 8px var(--neu-shadow-dark),
    inset -4px -4px 8px var(--neu-shadow-light);
}

/* ============================================================
   Layout & Container
   ============================================================ */

main {
  max-width: 1040px;
  margin: 0 auto;
  padding: 0 24px 96px;
}

.section-title {
  text-align: center;
  font-size: 24px;
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--text);
  margin-bottom: 40px;
  text-wrap: balance;
}

/* ============================================================
   Header & Glassmorphic Sticky Navigation
   ============================================================ */

.site-nav {
  position: sticky;
  top: 16px;
  z-index: 40;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 14px 24px;
  margin: 16px 0 48px;
  background: var(--surface-glass);
  backdrop-filter: blur(24px) saturate(180%);
  -webkit-backdrop-filter: blur(24px) saturate(180%);
  border: 1px solid var(--border);
  border-radius: 999px;
  box-shadow:
    inset 0 1px 0 0 rgba(255, 255, 255, 0.12),
    0 1px 2px 0 rgba(0, 0, 0, 0.30),
    0 12px 24px -4px rgba(0, 0, 0, 0.40);
}

.nav-brand {
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text);
  text-decoration: none;
}

.hero-logo-accent {
  color: var(--accent-bright);
}

.nav-links {
  display: flex;
  gap: 8px;
  list-style: none;
}

.nav-link {
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--text-muted);
  text-decoration: none;
  padding: 8px 14px;
  border-radius: 999px;
  transition:
    color 0.18s var(--ease-out-expo),
    background-color 0.18s var(--ease-out-expo),
    transform 0.18s var(--ease-out-expo);
}

.nav-link:hover {
  color: var(--text);
  background-color: rgba(255, 255, 255, 0.08);
}

.nav-link:active {
  transform: scale(0.97);
}

/* ============================================================
   Hero Section
   ============================================================ */

.hero {
  text-align: center;
  padding: 64px 0 72px;
}

.hero-logo {
  font-size: clamp(44px, 7vw, 76px);
  font-weight: 700;
  letter-spacing: -0.035em;
  color: var(--text);
  line-height: 1.05;
  margin-bottom: 20px;
  text-wrap: balance;
}

.hero-tagline {
  font-size: clamp(17px, 2.2vw, 21px);
  font-weight: 400;
  color: var(--text-muted);
  max-width: 56ch;
  margin: 0 auto 40px;
  line-height: 1.55;
  letter-spacing: -0.01em;
  text-wrap: pretty;
}

/* ============================================================
   Keyboard Shortcuts Bar (Recessed Well -> Extruded Key Caps)
   ============================================================ */

.shortcuts-bar {
  margin: 28px auto 0;
  max-width: 640px;
  background-color: var(--surface-dark);
  border: 1px solid var(--border-inset);
  border-radius: var(--radius-lg);
  box-shadow:
    inset 4px 4px 8px var(--neu-shadow-dark),
    inset -4px -4px 8px var(--neu-shadow-light);
  padding: 12px 24px;
  display: flex;
  justify-content: center;
  align-items: center;
  flex-wrap: wrap;
  gap: 20px;
}

.shortcut-item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-muted);
}

.key-badge {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
  padding: 3px 8px;
  background: linear-gradient(145deg, var(--surface), var(--surface-dark));
  color: var(--text);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  box-shadow:
    inset 0 1px 0 0 var(--specular),
    3px 3px 6px var(--neu-shadow-dark),
    -3px -3px 6px var(--neu-shadow-light);
}

/* ============================================================
   Downloads Section (Tactile Extruded Neumorphic Cards)
   ============================================================ */

.downloads {
  padding: 40px 0 64px;
}

.download-buttons {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 24px;
  max-width: 760px;
  margin: 0 auto;
}

.download-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  padding: 32px 24px;
  background: linear-gradient(145deg, var(--surface), var(--surface-dark));
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  color: var(--text);
  text-decoration: none;
  cursor: pointer;
  box-shadow:
    inset 0 1px 0 0 var(--specular),
    8px 8px 16px var(--neu-shadow-dark),
    -8px -8px 16px var(--neu-shadow-light);
  transition:
    transform 0.2s var(--ease-out-expo),
    border-color 0.2s var(--ease-out-expo),
    box-shadow 0.2s var(--ease-out-expo);
}

.download-btn:hover {
  transform: translateY(-2px);
  border-color: var(--accent-bright);
  box-shadow:
    inset 0 1px 0 0 rgba(255, 255, 255, 0.16),
    10px 10px 20px var(--neu-shadow-dark),
    -10px -10px 20px var(--neu-shadow-light);
}

.download-btn:active {
  transform: scale(0.97);
  border-color: var(--border-inset);
  box-shadow:
    inset 4px 4px 8px var(--neu-shadow-dark),
    inset -4px -4px 8px var(--neu-shadow-light);
}

.btn-icon {
  font-size: 38px;
  line-height: 1;
}

.btn-title {
  font-size: 17px;
  font-weight: 600;
  letter-spacing: -0.015em;
  color: var(--text);
}

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

/* ============================================================
   How It Works Section (Bento Feature Cards)
   ============================================================ */

.how-it-works {
  padding: 48px 0 64px;
}

.steps {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 24px;
}

.step {
  background: linear-gradient(145deg, var(--surface), var(--surface-dark));
  border: 1px solid var(--border);
  border-radius: var(--radius-xl);
  box-shadow:
    inset 0 1px 0 0 var(--specular),
    8px 8px 16px var(--neu-shadow-dark),
    -8px -8px 16px var(--neu-shadow-light);
  padding: 32px 24px;
  text-align: left;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.step-number {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  font-variant-numeric: tabular-nums;
  color: var(--led-cyan);
  letter-spacing: 0.06em;
}

.step-title {
  font-size: 19px;
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.02em;
  color: var(--text);
}

.step-text {
  font-size: 15px;
  color: var(--text-muted);
  line-height: 1.55;
  letter-spacing: -0.01em;
  text-wrap: pretty;
}

/* ============================================================
   Footer
   ============================================================ */

.footer {
  margin-top: 64px;
  padding-top: 32px;
  border-top: 1px solid var(--border);
  text-align: center;
  font-size: 14px;
  color: var(--text-muted);
}

.footer-nav {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: 18px;
  margin-top: 16px;
  font-size: 13px;
}

.footer-link {
  color: var(--text-muted);
  text-decoration: none;
  transition: color 0.16s var(--ease-out-expo);
}

.footer-link:hover {
  color: var(--accent-bright);
  text-decoration: underline;
}

/* ============================================================
   Accessibility: Skip Link
   ============================================================ */

.skip-link {
  position: absolute;
  top: -120px;
  left: 20px;
  z-index: 10001;
  padding: 10px 18px;
  background-color: var(--surface);
  color: var(--text);
  font-size: 14px;
  font-weight: 600;
  text-decoration: none;
  border: 1px solid var(--accent-bright);
  border-radius: var(--radius-sm);
  transition: top 0.18s var(--ease-out-expo);
}

.skip-link:focus,
.skip-link:focus-visible {
  top: 20px;
}

/* ============================================================
   Legal Pages (Privacy & Terms)
   ============================================================ */

.legal-page {
  max-width: 860px;
  margin: 0 auto;
  padding: 32px 20px 80px;
}

.legal-header {
  margin-bottom: 36px;
  text-align: left;
}

.legal-title {
  font-size: clamp(28px, 5vw, 40px);
  font-weight: 700;
  line-height: 1.1;
  letter-spacing: -0.03em;
  color: var(--text);
  margin-bottom: 12px;
  text-wrap: balance;
}

.legal-badge {
  display: inline-block;
  padding: 5px 12px;
  background-color: var(--accent-subtle);
  color: var(--accent-bright);
  border: 1px solid rgba(41, 151, 255, 0.28);
  border-radius: 999px;
  font-size: 11px;
  font-weight: 600;
  letter-spacing: 0.06em;
  margin-bottom: 14px;
}

.legal-meta {
  font-size: 13px;
  font-variant-numeric: tabular-nums;
  color: var(--text-muted);
}

.legal-card {
  color: var(--text);
  padding: 40px 36px;
  margin-bottom: 36px;
  line-height: 1.65;
}

.legal-toc {
  padding: 20px 24px;
  margin-bottom: 32px;
}

.legal-toc h2 {
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.06em;
  margin-bottom: 12px;
  color: var(--text);
}

.legal-toc ul {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
  gap: 8px;
}

.legal-toc a {
  color: var(--accent-bright);
  text-decoration: none;
  font-size: 14px;
  font-variant-numeric: tabular-nums;
}

.legal-toc a:hover {
  text-decoration: underline;
}

.legal-section {
  margin-bottom: 36px;
  padding-bottom: 28px;
  border-bottom: 1px solid var(--border);
}

.legal-section:last-child {
  border-bottom: none;
}

.legal-section h2 {
  font-size: 20px;
  font-weight: 600;
  letter-spacing: -0.015em;
  color: var(--text);
  margin-top: 16px;
  margin-bottom: 12px;
}

.legal-section h3 {
  font-size: 16px;
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--text);
  margin-top: 20px;
  margin-bottom: 8px;
}

.legal-section p {
  font-size: 15px;
  color: var(--text-muted);
  margin-bottom: 14px;
  text-wrap: pretty;
}

.legal-section ul {
  margin-left: 24px;
  margin-bottom: 16px;
  font-size: 15px;
  color: var(--text-muted);
}

.legal-section li {
  margin-bottom: 6px;
}

.legal-table {
  width: 100%;
  border-collapse: collapse;
  margin: 20px 0;
  font-size: 14px;
}

.legal-table th,
.legal-table td {
  padding: 12px 16px;
  text-align: left;
  border: 1px solid var(--border);
}

.legal-table th {
  background-color: var(--surface-dark);
  font-weight: 600;
  color: var(--text);
}

.legal-table td {
  color: var(--text-muted);
}

.back-btn-row {
  display: flex;
  justify-content: flex-start;
  margin-bottom: 24px;
}

.back-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 10px 18px;
  border-radius: var(--radius-md);
  color: var(--text);
  text-decoration: none;
  font-size: 13px;
  font-weight: 600;
  transition:
    transform 0.16s var(--ease-out-expo),
    border-color 0.16s var(--ease-out-expo),
    box-shadow 0.16s var(--ease-out-expo);
}

.back-link:hover {
  transform: translateY(-1px);
  border-color: var(--accent-bright);
}

.back-link:active {
  transform: scale(0.97);
  box-shadow:
    inset 4px 4px 8px var(--neu-shadow-dark),
    inset -4px -4px 8px var(--neu-shadow-light);
}

/* ============================================================
   Accessibility: Reduced Motion Preference
   ============================================================ */

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto !important;
  }
}