:root {
  --bg: #f4f5f7;
  --bg-grid: #eef0f3;
  --surface: #ffffff;
  --surface-2: #fafbfc;
  --surface-tint: rgba(10, 132, 255, 0.05);
  --border: rgba(0, 0, 0, 0.08);
  --border-mid: rgba(0, 0, 0, 0.14);
  --border-strong: rgba(0, 0, 0, 0.22);
  --text: #1d1d1f;
  --text-dim: #4a4a4f;
  --text-muted: #86868b;
  --accent: #0a84ff;
  --accent-2: #007aff;
  --accent-3: #00b07a;
  --accent-warn: #ff9f0a;
  --grid-line: rgba(0, 0, 0, 0.05);
  --grid-line-strong: rgba(0, 0, 0, 0.09);
  --radius-lg: 16px;
  --radius-md: 12px;
  --radius-sm: 8px;
  --shadow-lg: 0 18px 50px -22px rgba(15, 30, 60, 0.22);
  --shadow-card: 0 1px 0 rgba(255, 255, 255, 0.9) inset, 0 1px 2px rgba(15, 30, 60, 0.04);
  --ease-apple: cubic-bezier(0.22, 0.61, 0.36, 1);
  --font-mono: "SF Mono", ui-monospace, "JetBrains Mono", "Menlo", "Consolas", monospace;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text",
    "Helvetica Neue", "Inter", system-ui, sans-serif;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  letter-spacing: -0.005em;
}

body {
  overflow-x: hidden;
  background-color: var(--bg);
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 40px 40px, 40px 40px;
  background-position: -1px -1px;
}

a { color: inherit; text-decoration: none; }

button { font-family: inherit; cursor: pointer; border: none; background: none; color: inherit; }

.container {
  width: 100%;
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 20px;
}

/* ---------- Nav ---------- */
.nav {
  position: sticky;
  top: 0;
  z-index: 50;
  background: rgba(244, 245, 247, 0.7);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s var(--ease-apple), background 0.3s var(--ease-apple);
}
.nav.scrolled { border-bottom-color: var(--border); background: rgba(244, 245, 247, 0.88); }

.nav-inner {
  max-width: 1080px;
  margin: 0 auto;
  padding: 12px 20px;
  display: flex;
  align-items: center;
  gap: 20px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-weight: 600;
  letter-spacing: -0.015em;
  font-size: 16px;
}

.brand-mark {
  width: 26px; height: 26px;
  display: grid;
  place-items: center;
  border-radius: 7px;
  background: linear-gradient(135deg, #0a84ff, #5ac8fa);
  color: #fff;
  box-shadow: 0 4px 12px -4px rgba(10, 132, 255, 0.5);
}

.nav-links {
  display: flex;
  gap: 20px;
  margin-left: auto;
  font-size: 13px;
  color: var(--text-dim);
}
.nav-links a { transition: color 0.2s var(--ease-apple); }
.nav-links a:hover { color: var(--text); }

.nav-cta {
  padding: 7px 14px;
  border-radius: 7px;
  background: var(--text);
  color: #fff;
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.005em;
  transition: transform 0.2s var(--ease-apple), background 0.2s var(--ease-apple);
  font-family: var(--font-mono);
  text-transform: uppercase;
}
.nav-cta:hover { transform: translateY(-1px); background: #000; }

@media (max-width: 720px) { .nav-links { display: none; } }

/* ---------- Hero ---------- */
.hero {
  position: relative;
  padding: 40px 0 32px;
  overflow: hidden;
  isolation: isolate;
}

.hero-bg { position: absolute; inset: 0; z-index: -1; pointer-events: none; }

.hero-bg::before, .hero-bg::after {
  content: "";
  position: absolute;
  border-radius: 50%;
  filter: blur(60px);
  opacity: 0.3;
}
.hero-bg::before {
  width: 380px; height: 380px;
  background: radial-gradient(circle, #5ac8fa 0%, transparent 65%);
  top: -100px; right: -100px;
}
.hero-bg::after {
  width: 300px; height: 300px;
  background: radial-gradient(circle, #b8e0ff 0%, transparent 65%);
  top: 40px; left: -100px;
}

.crosshair {
  position: absolute;
  width: 16px; height: 16px;
  pointer-events: none;
  opacity: 0.3;
}
.crosshair::before, .crosshair::after { content: ""; position: absolute; background: var(--text); }
.crosshair::before { top: 50%; left: 0; right: 0; height: 1px; transform: translateY(-0.5px); }
.crosshair::after { left: 50%; top: 0; bottom: 0; width: 1px; transform: translateX(-0.5px); }
.crosshair.tl { top: 56px; left: 20px; }
.crosshair.tr { top: 56px; right: 20px; }

.hero-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--border);
  padding-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
}
.hero-header .left { color: var(--accent); }

.hero-grid {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 28px;
  align-items: center;
  margin-top: 24px;
}

@media (max-width: 880px) {
  .hero-grid { grid-template-columns: 1fr; gap: 24px; }
}

.hero-text {
  display: flex;
  flex-direction: column;
  gap: 14px;
  align-items: flex-start;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  color: var(--accent);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 5px 10px;
  border-radius: 4px;
  background: var(--surface-tint);
  border: 1px solid rgba(10, 132, 255, 0.18);
  width: max-content;
}
.eyebrow::before {
  content: "";
  width: 6px; height: 6px;
  background: var(--accent);
  border-radius: 50%;
  box-shadow: 0 0 0 3px rgba(10, 132, 255, 0.18);
}

.display {
  font-size: clamp(34px, 6vw, 58px);
  line-height: 1.02;
  letter-spacing: -0.04em;
  font-weight: 700;
  margin: 0;
  max-width: 14ch;
}

.grad {
  background: linear-gradient(120deg, #0a84ff, #00b07a 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.lede {
  font-size: clamp(15px, 1.4vw, 17px);
  line-height: 1.5;
  color: var(--text-dim);
  max-width: 52ch;
  margin: 0;
}
.lede strong { color: var(--text); font-weight: 600; }

.hero-actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  margin-top: 4px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  padding: 10px 16px;
  border-radius: 8px;
  font-size: 14px;
  font-weight: 500;
  letter-spacing: 0.005em;
  transition: transform 0.2s var(--ease-apple), background 0.2s var(--ease-apple),
    color 0.2s var(--ease-apple), box-shadow 0.3s var(--ease-apple),
    border-color 0.2s var(--ease-apple);
  border: 1px solid transparent;
}

.btn-primary {
  background: var(--accent);
  color: #fff;
  box-shadow: 0 6px 16px -8px rgba(10, 132, 255, 0.6);
}
.btn-primary:hover {
  transform: translateY(-1px);
  background: #006bdb;
  box-shadow: 0 10px 22px -10px rgba(10, 132, 255, 0.75);
}
.btn-ghost {
  background: var(--surface);
  color: var(--text);
  border-color: var(--border-mid);
}
.btn-ghost:hover { background: var(--surface-2); border-color: var(--border-strong); }

.btn .arrow { font-family: var(--font-mono); transition: transform 0.2s var(--ease-apple); }
.btn:hover .arrow { transform: translateX(2px); }

.hero-meta {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0;
  padding: 12px 0 0;
  margin: 6px 0 0;
  border-top: 1px solid var(--border);
  width: 100%;
}

@media (max-width: 640px) {
  .hero-meta { grid-template-columns: 1fr; gap: 4px; }
}

.hero-meta li {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 4px 0;
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--text);
}

.hero-meta .key {
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
}

/* ---------- Phone visual ---------- */
.hero-visual {
  display: grid;
  place-items: center;
  position: relative;
  min-height: 380px;
}

.phone-stage {
  position: relative;
  width: 220px;
  display: flex;
  flex-direction: column;
  align-items: center;
}

.phone-body {
  position: relative;
  width: 180px;
  height: 320px;
  border-radius: 32px;
  background: linear-gradient(180deg, #2a2a2e, #1a1a1c);
  padding: 6px 6px 14px;
  box-shadow:
    0 32px 60px -28px rgba(15, 30, 60, 0.45),
    0 0 0 1px rgba(0, 0, 0, 0.04),
    inset 0 0 0 1.5px rgba(255, 255, 255, 0.06);
}

.phone-notch {
  position: absolute;
  top: 14px;
  left: 50%;
  transform: translateX(-50%);
  width: 58px;
  height: 14px;
  background: #000;
  border-radius: 10px;
  z-index: 3;
}

.phone-notch::after {
  content: "";
  position: absolute;
  right: 7px;
  top: 50%;
  transform: translateY(-50%);
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: radial-gradient(circle at 35% 35%, #4a6c9a, #14233a);
  box-shadow: inset 0 0 0 0.5px rgba(120, 160, 230, 0.4);
}

.phone-screen {
  position: relative;
  width: 100%;
  height: 100%;
  border-radius: 26px;
  background: linear-gradient(165deg, #e7f0ff 0%, #f5f9ff 55%, #f0eaff 100%);
  padding: 28px 14px 12px;
  display: flex;
  flex-direction: column;
  gap: 4px;
  overflow: hidden;
}

.screen-label {
  font-family: var(--font-mono);
  font-size: 9px;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--accent);
}

.screen-freq {
  font-family: var(--font-mono);
  font-size: 30px;
  color: var(--text);
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.02em;
  line-height: 1;
  margin-top: 4px;
}

.screen-freq .hz {
  font-size: 11px;
  color: var(--text-muted);
  margin-left: 2px;
}

.screen-wave {
  width: 100%;
  height: 26px;
  margin-top: auto;
  color: var(--accent);
  opacity: 0.85;
  animation: wave-shimmer 1.4s ease-in-out infinite;
}

@keyframes wave-shimmer {
  0%, 100% { opacity: 0.55; }
  50%      { opacity: 1; }
}

.screen-status {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 9px;
  color: var(--accent-3);
  text-transform: uppercase;
  letter-spacing: 0.12em;
  margin-top: 4px;
}

.dot-live {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--accent-3);
  box-shadow: 0 0 0 3px rgba(0, 176, 122, 0.18);
  animation: pulse 1.4s ease-in-out infinite;
}

.phone-grille {
  position: absolute;
  bottom: 4px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 2.5px;
  z-index: 4;
}

.phone-grille span {
  width: 2.5px;
  height: 2.5px;
  border-radius: 50%;
  background: #6a6a70;
}

.sound-waves {
  position: relative;
  width: 220px;
  height: 70px;
  margin-top: 2px;
  pointer-events: none;
}

.sw {
  position: absolute;
  left: 50%;
  top: 0;
  width: 80px;
  height: 38px;
  margin-left: -40px;
  border: 1.5px solid var(--accent);
  border-top: none;
  border-radius: 0 0 80px 80px;
  opacity: 0;
  transform-origin: top center;
  animation: emit 2.6s ease-out infinite;
}

.sw1 { animation-delay: 0s; }
.sw2 { animation-delay: 0.85s; }
.sw3 { animation-delay: 1.7s; }

@keyframes emit {
  0%   { transform: scale(0.35); opacity: 0; }
  20%  { opacity: 0.85; }
  100% { transform: scale(2.0); opacity: 0; }
}

.droplet {
  position: absolute;
  width: 5px;
  height: 7px;
  border-radius: 50% 50% 50% 50% / 60% 60% 40% 40%;
  background: var(--accent);
  opacity: 0;
  animation: drop 3.2s ease-in infinite;
}

.droplet.d1 { left: calc(50% - 14px); top: 2px; animation-delay: 0.4s; }
.droplet.d2 { left: calc(50% + 9px); top: 2px; animation-delay: 1.9s; }

@keyframes drop {
  0%   { transform: translateY(0); opacity: 0; }
  15%  { opacity: 0.85; }
  60%  { opacity: 0.5; }
  100% { transform: translateY(55px); opacity: 0; }
}

.phone-annot {
  position: absolute;
  display: flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
  white-space: nowrap;
  z-index: 2;
}

.ann-line {
  display: block;
  height: 1px;
  width: 38px;
  background-image: linear-gradient(to right, var(--text-muted) 50%, transparent 50%);
  background-size: 4px 1px;
  background-repeat: repeat-x;
}

.annot-cam {
  top: 18px;
  right: 0;
  transform: translateX(110%);
  flex-direction: row-reverse;
}

.annot-speaker {
  top: 280px;
  left: 0;
  transform: translateX(-110%);
}

@media (max-width: 880px) {
  .hero-visual { min-height: 340px; }
}

@media (max-width: 640px) {
  .annot-cam, .annot-speaker { display: none; }
}

/* ---------- Player ---------- */
.player { padding: 16px 0 48px; }

.player-card {
  position: relative;
  border-radius: var(--radius-lg);
  background: var(--surface);
  border: 1px solid var(--border);
  padding: 0;
  box-shadow: var(--shadow-lg);
  overflow: hidden;
}

.panel-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 11px 18px;
  border-bottom: 1px solid var(--border);
  background: var(--surface-2);
  font-family: var(--font-mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
}

.panel-head .dots { display: inline-flex; gap: 6px; }
.panel-head .dots span {
  width: 9px; height: 9px;
  border-radius: 50%;
  background: #d0d2d6;
}
.panel-head .dots span:nth-child(1) { background: #ff6058; }
.panel-head .dots span:nth-child(2) { background: #ffbe2f; }
.panel-head .dots span:nth-child(3) { background: #29c93c; }

.panel-title { margin-left: 12px; flex: 1; color: var(--text); font-weight: 500; }
.panel-id { color: var(--accent); }

.player-top {
  display: flex;
  justify-content: space-between;
  align-items: stretch;
  padding: 18px 18px 6px;
  gap: 18px;
}

.status {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.status-dot {
  width: 8px; height: 8px;
  border-radius: 50%;
  background: #b0b0b6;
  transition: background 0.3s var(--ease-apple), box-shadow 0.3s var(--ease-apple);
}

.status-dot.active {
  background: var(--accent-3);
  box-shadow: 0 0 0 4px rgba(0, 176, 122, 0.18);
  animation: pulse 1.4s ease-in-out infinite;
}

@keyframes pulse { 0%, 100% { opacity: 1; } 50% { opacity: 0.55; } }

.freq-display {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 30px;
  font-weight: 500;
  letter-spacing: -0.01em;
  color: var(--text);
  line-height: 1;
}

.freq-display .unit {
  font-size: 13px;
  color: var(--text-muted);
  margin-left: 4px;
  font-weight: 400;
}

.play-stage {
  position: relative;
  padding: 4px 18px 14px;
  display: grid;
  place-items: center;
}

.play-btn {
  position: relative;
  width: 130px;
  height: 130px;
  display: grid;
  place-items: center;
  border-radius: 50%;
  background: #fff;
  border: 1px solid var(--border-mid);
  box-shadow:
    0 0 0 6px rgba(10, 132, 255, 0.04),
    0 14px 32px -14px rgba(10, 132, 255, 0.4),
    inset 0 0 0 1px rgba(255, 255, 255, 0.8);
  color: var(--accent);
  transition: transform 0.25s var(--ease-apple), box-shadow 0.3s var(--ease-apple);
}

.play-btn:hover {
  transform: scale(1.02);
  box-shadow:
    0 0 0 10px rgba(10, 132, 255, 0.06),
    0 18px 40px -14px rgba(10, 132, 255, 0.55);
}

.play-btn:active { transform: scale(0.98); }

.play-btn.playing { background: var(--accent); color: #fff; border-color: var(--accent); }

.play-icon, .pause-icon {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  transition: opacity 0.2s var(--ease-apple), transform 0.3s var(--ease-apple);
}

.play-icon { transform: translateX(3px); }
.pause-icon { opacity: 0; transform: scale(0.8); }

.play-btn.playing .play-icon { opacity: 0; transform: scale(0.8); }
.play-btn.playing .pause-icon { opacity: 1; transform: scale(1); }

.play-ring {
  position: absolute;
  inset: -2px;
  border-radius: 50%;
  border: 1.5px solid rgba(10, 132, 255, 0.5);
  opacity: 0;
  pointer-events: none;
}

.play-btn.playing .play-ring { animation: ring 2.4s ease-out infinite; }
.play-btn.playing .play-ring-2 { animation-delay: 0.8s; }
.play-btn.playing .play-ring-3 { animation-delay: 1.6s; }

@keyframes ring {
  0% { transform: scale(1); opacity: 0.6; }
  100% { transform: scale(1.6); opacity: 0; }
}

.player-hint {
  text-align: center;
  color: var(--text-dim);
  font-size: 13px;
  max-width: 38ch;
  margin: 0 auto;
  padding: 0 18px 8px;
  line-height: 1.4;
}

/* Telemetry */
.telemetry {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
  background: var(--surface-2);
  font-family: var(--font-mono);
}

.telemetry-cell {
  padding: 10px 14px;
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.telemetry-cell:last-child { border-right: none; }

.telemetry-key {
  font-size: 9px;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
}

.telemetry-val {
  font-size: 13px;
  color: var(--text);
  font-variant-numeric: tabular-nums;
}

@media (max-width: 640px) {
  .telemetry { grid-template-columns: repeat(2, 1fr); }
  .telemetry-cell:nth-child(2) { border-right: none; }
  .telemetry-cell:nth-child(1), .telemetry-cell:nth-child(2) {
    border-bottom: 1px solid var(--border);
  }
}

/* Visualizer */
.visualizer {
  position: relative;
  height: 96px;
  background: #fafbfc;
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 16px 16px;
  border-bottom: 1px solid var(--border);
  overflow: hidden;
}

.visualizer canvas { width: 100%; height: 100%; display: block; }

.viz-axis {
  position: absolute;
  font-family: var(--font-mono);
  font-size: 9px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--text-muted);
}

.viz-axis.top-left { top: 6px; left: 10px; }
.viz-axis.top-right { top: 6px; right: 10px; }
.viz-axis.bottom-left { bottom: 6px; left: 10px; }

/* Controls */
.controls {
  display: grid;
  grid-template-columns: 1fr 1fr;
  background: var(--surface);
}

@media (max-width: 640px) { .controls { grid-template-columns: 1fr; } }

.control {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 4px 14px;
  padding: 14px 18px;
  border-right: 1px solid var(--border);
}

.control:last-child { border-right: none; }

@media (max-width: 640px) {
  .control { border-right: none; border-bottom: 1px solid var(--border); }
  .control:last-child { border-bottom: none; }
}

.control-label {
  font-family: var(--font-mono);
  font-size: 10px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--text-muted);
}

.control-value {
  font-family: var(--font-mono);
  font-size: 12px;
  font-variant-numeric: tabular-nums;
  color: var(--text);
  text-align: right;
}

.control input[type="range"] { grid-column: 1 / -1; margin-top: 2px; }

input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 4px;
  background: linear-gradient(to right, var(--accent) var(--p, 80%), rgba(0, 0, 0, 0.1) var(--p, 80%));
  border-radius: 999px;
  outline: none;
}

input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 15px; height: 15px;
  border-radius: 50%;
  background: #fff;
  border: 1px solid var(--border-strong);
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.15);
  cursor: pointer;
  transition: transform 0.15s var(--ease-apple);
}

input[type="range"]::-webkit-slider-thumb:hover { transform: scale(1.15); }

input[type="range"]::-moz-range-thumb {
  width: 15px; height: 15px;
  border-radius: 50%;
  background: #fff;
  border: 1px solid var(--border-strong);
  cursor: pointer;
}

/* ---------- Section heads ---------- */
.section-head {
  display: grid;
  grid-template-columns: 80px 1fr;
  gap: 16px;
  align-items: start;
  max-width: 960px;
  margin: 0 auto 28px;
  padding-bottom: 18px;
  border-bottom: 1px solid var(--border);
}

.section-num {
  font-family: var(--font-mono);
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
  padding-top: 6px;
}

.section-head-text { display: flex; flex-direction: column; gap: 8px; }

.section-head h2 {
  font-size: clamp(24px, 3.6vw, 36px);
  letter-spacing: -0.03em;
  line-height: 1.08;
  font-weight: 700;
  margin: 0;
}

.section-sub {
  color: var(--text-dim);
  font-size: 15px;
  line-height: 1.5;
  margin: 0;
  max-width: 58ch;
}

@media (max-width: 640px) {
  .section-head { grid-template-columns: 1fr; gap: 6px; }
}

/* ---------- Explainer ---------- */
.explainer { padding: 32px 0 16px; }

.explainer-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface);
  overflow: hidden;
  box-shadow: var(--shadow-card);
}

@media (max-width: 880px) { .explainer-grid { grid-template-columns: 1fr; } }

.explainer-card {
  padding: 22px;
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.explainer-card:last-child { border-right: none; }

@media (max-width: 880px) {
  .explainer-card { border-right: none; border-bottom: 1px solid var(--border); }
  .explainer-card:last-child { border-bottom: none; }
}

.explainer-icon {
  width: 36px;
  height: 36px;
  display: grid;
  place-items: center;
  color: var(--accent);
  background: var(--surface-tint);
  border: 1px solid rgba(10, 132, 255, 0.18);
  border-radius: 8px;
  margin-bottom: 2px;
}

.explainer-num {
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 500;
  color: var(--text-muted);
  letter-spacing: 0.1em;
  text-transform: uppercase;
}

.explainer-card h3 {
  margin: 2px 0 0;
  font-size: 17px;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.explainer-card p {
  margin: 0;
  color: var(--text-dim);
  font-size: 14px;
  line-height: 1.5;
}

/* ---------- Modes ---------- */
.modes { padding: 48px 0; }

.mode-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface);
  overflow: hidden;
  box-shadow: var(--shadow-card);
}

@media (max-width: 880px) { .mode-grid { grid-template-columns: 1fr; } }

.mode {
  text-align: left;
  padding: 20px;
  border-right: 1px solid var(--border);
  background: var(--surface);
  display: flex;
  flex-direction: column;
  gap: 8px;
  transition: background 0.2s var(--ease-apple);
  position: relative;
  overflow: hidden;
}

.mode:last-child { border-right: none; }

@media (max-width: 880px) {
  .mode { border-right: none; border-bottom: 1px solid var(--border); }
  .mode:last-child { border-bottom: none; }
}

.mode:hover { background: var(--surface-2); }
.mode.active { background: var(--surface-tint); }

.mode.active::before {
  content: "";
  position: absolute;
  left: 0; top: 0; bottom: 0;
  width: 3px;
  background: var(--accent);
}

.mode-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
}

.mode-icon {
  width: 32px; height: 32px;
  border-radius: 7px;
  display: grid;
  place-items: center;
  background: var(--surface-tint);
  color: var(--accent);
  border: 1px solid rgba(10, 132, 255, 0.2);
}

.mode-tag {
  font-family: var(--font-mono);
  font-size: 9px;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--text-muted);
  padding: 3px 7px;
  border: 1px solid var(--border);
  border-radius: 4px;
  background: var(--surface-2);
}

.mode h3 {
  margin: 6px 0 0;
  font-size: 17px;
  letter-spacing: -0.01em;
  font-weight: 600;
}

.mode p {
  margin: 0;
  color: var(--text-dim);
  font-size: 14px;
  line-height: 1.45;
}

.mode-stats {
  margin-top: auto;
  padding-top: 12px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0 12px;
  border-top: 1px dashed var(--border-mid);
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.mode-stats .v { color: var(--text); font-size: 12px; text-transform: none; letter-spacing: 0; }

/* ---------- How ---------- */
.how { padding: 48px 0; }

.steps {
  list-style: none;
  padding: 0;
  margin: 0;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface);
  overflow: hidden;
  box-shadow: var(--shadow-card);
}

@media (max-width: 880px) { .steps { grid-template-columns: 1fr; } }

.step {
  padding: 22px;
  border-right: 1px solid var(--border);
  position: relative;
}

.step:last-child { border-right: none; }

@media (max-width: 880px) {
  .step { border-right: none; border-bottom: 1px solid var(--border); }
  .step:last-child { border-bottom: none; }
}

.step-num {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 500;
  color: var(--accent);
  letter-spacing: 0.1em;
  padding: 3px 7px;
  border-radius: 4px;
  background: var(--surface-tint);
  border: 1px solid rgba(10, 132, 255, 0.18);
}

.step h3 {
  margin: 12px 0 6px;
  font-size: 17px;
  font-weight: 600;
  letter-spacing: -0.01em;
}

.step p {
  margin: 0;
  color: var(--text-dim);
  font-size: 14px;
  line-height: 1.5;
}

/* ---------- Specs ---------- */
.specs { padding: 20px 0 48px; }

.specs-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface);
  overflow: hidden;
  box-shadow: var(--shadow-card);
}

@media (max-width: 980px) { .specs-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 520px) { .specs-grid { grid-template-columns: 1fr; } }

.spec-card {
  padding: 18px;
  border-right: 1px solid var(--border);
}

.spec-card:last-child { border-right: none; }

@media (max-width: 980px) {
  .spec-card:nth-child(2) { border-right: none; }
  .spec-card:nth-child(1), .spec-card:nth-child(2) {
    border-bottom: 1px solid var(--border);
  }
}

@media (max-width: 520px) {
  .spec-card { border-right: none; border-bottom: 1px solid var(--border); }
  .spec-card:last-child { border-bottom: none; }
}

.spec-card h3 {
  margin: 0 0 6px;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: -0.01em;
  color: var(--text);
  display: flex;
  align-items: baseline;
  gap: 8px;
}

.spec-card .badge {
  font-family: var(--font-mono);
  font-size: 9px;
  color: var(--accent-3);
  background: rgba(0, 176, 122, 0.1);
  padding: 2px 6px;
  border-radius: 3px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}

.spec-card p {
  margin: 0;
  color: var(--text-dim);
  font-size: 13px;
  line-height: 1.5;
}

/* ---------- FAQ ---------- */
.faq { padding: 48px 0; }

.faq-list {
  max-width: 780px;
  margin: 0 auto;
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface);
  overflow: hidden;
  box-shadow: var(--shadow-card);
  counter-reset: faq;
}

.faq-list details {
  border-bottom: 1px solid var(--border);
  padding: 14px 18px;
  transition: background 0.2s var(--ease-apple);
}

.faq-list details:last-child { border-bottom: none; }
.faq-list details[open] { background: var(--surface-2); }

.faq-list summary {
  list-style: none;
  cursor: pointer;
  font-size: 15px;
  font-weight: 500;
  letter-spacing: -0.005em;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  color: var(--text);
}

.faq-list summary::-webkit-details-marker { display: none; }

.faq-list summary::before {
  content: counter(faq, decimal-leading-zero);
  counter-increment: faq;
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--accent);
  margin-right: 12px;
  letter-spacing: 0.08em;
  min-width: 22px;
}

.faq-list summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 18px;
  font-weight: 400;
  color: var(--text-muted);
  transition: transform 0.25s var(--ease-apple);
  flex-shrink: 0;
  width: 18px;
  text-align: center;
}

.faq-list details[open] summary::after { content: "−"; color: var(--accent); }

.faq-list p {
  margin: 10px 0 2px;
  color: var(--text-dim);
  font-size: 14px;
  line-height: 1.55;
  padding-left: 34px;
}

/* ---------- CTA Band ---------- */
.cta-band { padding: 32px 0 48px; }

.cta-inner {
  border-radius: var(--radius-md);
  padding: 36px 28px;
  background: var(--surface);
  border: 1px solid var(--border);
  text-align: center;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 14px;
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-card);
}

.cta-inner::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--grid-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px);
  background-size: 28px 28px;
  opacity: 0.6;
  pointer-events: none;
}

.cta-inner > * { position: relative; }

.cta-inner h2 {
  margin: 0;
  font-size: clamp(24px, 3.4vw, 32px);
  font-weight: 700;
  letter-spacing: -0.03em;
}

.cta-tag {
  font-family: var(--font-mono);
  font-size: 10px;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.12em;
}

/* ---------- Footer ---------- */
.footer {
  padding: 24px 0 40px;
  border-top: 1px solid var(--border);
  margin-top: 16px;
  background: var(--surface);
}

.footer-inner {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 20px;
}

@media (max-width: 720px) {
  .footer-inner { grid-template-columns: 1fr; text-align: center; justify-items: center; }
}

.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-weight: 600;
  font-size: 14px;
}

.footer-note {
  color: var(--text-muted);
  font-size: 12px;
  line-height: 1.5;
  margin: 0;
  max-width: 58ch;
}

.footer-copy {
  color: var(--text-muted);
  font-size: 11px;
  margin: 0;
  font-family: var(--font-mono);
  letter-spacing: 0.04em;
}

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation: none !important;
    transition: none !important;
  }
  html { scroll-behavior: auto; }
}