@charset "UTF-8";

:root {
  --bg: #ffffff;
  --panel: #f6f8fc;
  --panel-border: rgba(12, 25, 50, 0.08);
  --text: #0b172d;
  --muted: #5c6a80;
  --accent: #27c7a8;
  --accent-strong: #ffae4d;
  --success: #1f9d67;
  --warning: #ff8a3d;
  --danger: #e05d70;
  --channel-r: #ff6b6b;
  --channel-g: #2fbf71;
  --channel-b: #4d7cff;
  --shadow: 0 20px 60px rgba(12, 25, 50, 0.1);
  --radius-lg: 24px;
  --radius-sm: 14px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Space Grotesk", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--text);
  background: var(--bg);
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 48px 18px;
}

.page-shell {
  width: min(1200px, 100%);
  display: grid;
  gap: 24px;
}

.hero {
  text-align: left;
  max-width: 720px;
  line-height: 1.5;
}

.eyebrow {
  letter-spacing: 0.16em;
  text-transform: uppercase;
  font-size: 13px;
  color: var(--accent);
  margin: 0 0 8px;
}

h1 {
  margin: 0 0 8px;
  font-size: clamp(28px, 4vw, 40px);
  font-weight: 700;
  letter-spacing: -0.02em;
}

.lede {
  margin: 0;
  color: var(--muted);
  font-size: 17px;
}

.card {
  background: var(--panel);
  border: 1px solid var(--panel-border);
  border-radius: var(--radius-lg);
  padding: 28px;
  box-shadow: var(--shadow);
  backdrop-filter: blur(10px);
}

.colors {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 18px;
  margin-bottom: 20px;
}

.color-stack {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--panel-border);
  border-radius: var(--radius-sm);
  padding: 16px;
}

.label {
  margin: 0 0 8px;
  color: var(--muted);
  font-size: 14px;
  letter-spacing: 0.03em;
}

.color-box {
  width: 100%;
  height: 180px;
  border-radius: 12px;
  border: 1px solid rgba(255, 255, 255, 0.08);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.1);
}

.controls {
  display: grid;
  gap: 16px;
}

.sliders {
  display: grid;
  gap: 10px;
}

.actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
}

label {
  display: grid;
  grid-template-columns: 26px 1fr auto;
  align-items: center;
  gap: 12px;
  color: var(--text);
  font-weight: 600;
}

input[type="range"] {
  width: 100%;
  appearance: none;
  height: 6px;
  border-radius: 999px;
  background: linear-gradient(90deg, rgba(108, 224, 195, 0.5), rgba(255, 182, 95, 0.5));
  outline: none;
}

input[type="range"]::-webkit-slider-thumb {
  appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: #fff;
  border: 2px solid var(--accent);
  box-shadow: 0 6px 12px rgba(0, 0, 0, 0.25);
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}

input[type="range"]:active::-webkit-slider-thumb {
  transform: scale(1.05);
  box-shadow: 0 10px 24px rgba(0, 0, 0, 0.35);
}

button {
  justify-self: start;
  padding: 12px 26px;
  border-radius: 14px;
  border: 1px solid transparent;
  background: linear-gradient(120deg, var(--accent), var(--accent-strong));
  color: #0a0d12;
  font-weight: 700;
  font-size: 16px;
  letter-spacing: 0.01em;
  cursor: pointer;
  transition: transform 0.15s ease, box-shadow 0.15s ease, filter 0.15s ease;
  box-shadow: 0 12px 24px rgba(0, 0, 0, 0.3);
}

button:hover {
  transform: translateY(-1px);
  box-shadow: 0 16px 32px rgba(0, 0, 0, 0.38);
  filter: saturate(1.05);
}

button:active {
  transform: translateY(0);
}

.ghost {
  background: transparent;
  color: var(--text);
  border: 1px solid var(--panel-border);
  box-shadow: none;
}

.ghost:hover {
  transform: translateY(-1px);
  border-color: rgba(255, 255, 255, 0.4);
}

.result {
  margin: 0;
  color: var(--muted);
  font-size: 15px;
}

.result.perfect {
  color: var(--success);
}

.result.good {
  color: var(--warning);
}

.result.try {
  color: var(--danger);
}

.rgb-info {
  margin-top: 12px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--panel-border);
  border-radius: var(--radius-sm);
  padding: 14px 16px;
  font-size: 14px;
  color: var(--muted);
  line-height: 1.5;
}

.rgb-info strong {
  color: var(--text);
}

@media (max-width: 640px) {
  .card {
    padding: 22px;
  }

  .color-box {
    height: 150px;
  }
}