/*
 * style.css — shared styles for DiffractLab (light engineering theme).
 */
:root {
  --bg: #f4f6f9;
  --card: #ffffff;
  --border: #dde3ea;
  --text: #1c2733;
  --muted: #5c6b7a;
  --primary: #0b6bcb;
  --primary-dark: #084f96;
  --accent: #0d8a72;
  --danger: #c0392b;
  --warn-bg: #fdf3e3;
  --warn-border: #e8b34b;
  --ok-bg: #e6f6ee;
  --ok-border: #2e9e6b;
  --code-bg: #eef2f6;
  --radius: 8px;
  --shadow: 0 1px 3px rgba(16, 36, 58, .08);
}

* { box-sizing: border-box; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Segoe UI", "Helvetica Neue", Arial, "PingFang SC", "Microsoft YaHei", sans-serif;
  font-size: 15px;
  line-height: 1.55;
}

a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ---------------- top bar ---------------- */
.topbar {
  position: sticky;
  top: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  gap: 14px;
  flex-wrap: wrap;
  padding: 10px 22px;
  background: #10243a;
  color: #eaf1f8;
  box-shadow: 0 2px 8px rgba(0, 0, 0, .18);
}
.topbar .brand {
  font-weight: 700;
  font-size: 17px;
  letter-spacing: .3px;
  color: #fff;
  display: flex;
  align-items: center;
  gap: 8px;
}
.topbar .brand .dot { color: #4fc3f7; }
.topbar nav {
  display: flex;
  align-items: center;
  gap: 4px;
  flex-wrap: wrap;
  margin-left: 6px;
}
.topbar nav a {
  color: #c8d6e5;
  padding: 6px 12px;
  border-radius: 6px;
  font-size: 14px;
}
.topbar nav a:hover { background: rgba(255, 255, 255, .12); color: #fff; text-decoration: none; }
.topbar nav a.active { background: rgba(79, 195, 247, .22); color: #fff; font-weight: 600; }
.topbar .spacer { flex: 1; }
.topbar .actions { display: flex; gap: 8px; align-items: center; flex-wrap: wrap; }
.btn-home {
  background: #0d8a72;
  color: #fff;
  border: none;
  padding: 7px 14px;
  border-radius: 6px;
  font-size: 13.5px;
  font-weight: 600;
  cursor: pointer;
  transition: background .15s;
}
.btn-home:hover { background: #0a6e5b; text-decoration: none; }
.btn-mail {
  background: transparent;
  color: #c8d6e5;
  border: 1px solid #3d5670;
  padding: 7px 14px;
  border-radius: 6px;
  font-size: 13.5px;
  cursor: pointer;
  transition: all .15s;
}
.btn-mail:hover { background: rgba(255, 255, 255, .1); color: #fff; border-color: #5a7898; }
.lang-select {
  background: #1b3a5a;
  color: #eaf1f8;
  border: 1px solid #3d5670;
  border-radius: 6px;
  padding: 6px 8px;
  font-size: 13px;
  cursor: pointer;
}
.lang-select:focus { outline: 1px solid #4fc3f7; }

/* ---------------- layout ---------------- */
.container { max-width: 1180px; margin: 0 auto; padding: 26px 20px 60px; }
.page-title { font-size: 26px; margin: 6px 0 4px; }
.page-sub { color: var(--muted); margin: 0 0 24px; }
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.grid-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.card {
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 20px;
}
.card h2 { margin: 0 0 12px; font-size: 17px; }
.card h3 { margin: 18px 0 8px; font-size: 15px; }
.card p { margin: 8px 0; }
.card ul { margin: 8px 0 8px 18px; padding: 0; }
.card li { margin: 5px 0; }
.lead { font-size: 16px; color: var(--text); }
.muted { color: var(--muted); }

/* tool layout */
.tool-grid {
  display: grid;
  grid-template-columns: 340px 1fr;
  gap: 20px;
  align-items: start;
}
@media (max-width: 900px) { .tool-grid { grid-template-columns: 1fr; } }

/* ---------------- forms ---------------- */
.form-group { margin-bottom: 14px; }
.form-group label {
  display: block;
  font-size: 13px;
  font-weight: 600;
  color: var(--muted);
  margin-bottom: 4px;
}
.form-group input[type="number"],
.form-group input[type="text"],
.form-group select {
  width: 100%;
  padding: 8px 10px;
  border: 1px solid var(--border);
  border-radius: 6px;
  font-size: 14px;
  background: #fff;
  color: var(--text);
}
.form-group input:focus, .form-group select:focus { outline: 2px solid rgba(11, 107, 203, .3); border-color: var(--primary); }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.form-row-3 { display: grid; grid-template-columns: 1fr 1fr 1fr; gap: 10px; }
.radio-row { display: flex; gap: 12px; align-items: center; }
.radio-row label { display: inline-flex; align-items: center; gap: 5px; font-weight: 500; color: var(--text); margin: 0; cursor: pointer; }
fieldset.layer-box {
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px;
  margin: 10px 0;
  background: #fafbfc;
}
fieldset.layer-box legend { font-size: 12.5px; font-weight: 700; color: var(--primary); padding: 0 6px; }
.layer-head { display: flex; justify-content: space-between; align-items: center; }
.layer-head .lyr-title { font-weight: 600; font-size: 14px; }
.btn-remove {
  background: none;
  border: 1px solid var(--danger);
  color: var(--danger);
  border-radius: 6px;
  padding: 3px 10px;
  font-size: 12.5px;
  cursor: pointer;
}
.btn-remove:hover { background: var(--danger); color: #fff; }
.hint { font-size: 12px; color: var(--muted); margin-top: 3px; }

/* ---------------- buttons ---------------- */
.btn {
  display: inline-block;
  border: none;
  border-radius: 6px;
  padding: 9px 16px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: background .15s;
}
.btn-primary { background: var(--primary); color: #fff; }
.btn-primary:hover { background: var(--primary-dark); }
.btn-accent { background: var(--accent); color: #fff; }
.btn-accent:hover { background: #0a6e5b; }
.btn-ghost { background: #fff; color: var(--primary); border: 1px solid var(--primary); }
.btn-ghost:hover { background: #eaf2fb; }
.btn-block { display: block; width: 100%; text-align: center; }
.btn-row { display: flex; gap: 10px; flex-wrap: wrap; margin-top: 8px; }
.btn:disabled { opacity: .55; cursor: not-allowed; }

/* ---------------- results ---------------- */
.stat-row { display: grid; grid-template-columns: repeat(3, 1fr); gap: 12px; margin-bottom: 16px; }
.stat-row-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; margin-bottom: 16px; }
@media (max-width: 700px) { .stat-row, .stat-row-4 { grid-template-columns: 1fr; } }
.stat {
  background: #fafbfc;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 12px 14px;
  text-align: center;
}
.stat .k { font-size: 12.5px; color: var(--muted); }
.stat .v { font-size: 20px; font-weight: 700; margin-top: 2px; }
.stat.ok .v { color: var(--ok-border); }
.stat.warn .v { color: var(--warn-border); }

table.data {
  width: 100%;
  border-collapse: collapse;
  font-size: 13.5px;
  margin: 10px 0 4px;
}
table.data th, table.data td {
  border: 1px solid var(--border);
  padding: 6px 9px;
  text-align: right;
}
table.data th { background: #eef3f8; font-weight: 600; }
table.data td:first-child, table.data th:first-child { text-align: left; }
table.data tr:nth-child(even) td { background: #f8fafc; }

canvas.chart {
  width: 100%;
  height: 300px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: #fff;
  display: block;
}
.chart-wrap { margin-top: 16px; }
.chart-wrap h3 { margin-bottom: 6px; }
.legend { display: flex; gap: 16px; font-size: 13px; color: var(--muted); margin-bottom: 6px; }
.legend .sw { display: inline-block; width: 12px; height: 12px; border-radius: 3px; margin-right: 5px; vertical-align: -1px; }

.badge {
  display: inline-block;
  padding: 2px 9px;
  border-radius: 10px;
  font-size: 12px;
  font-weight: 700;
}
.badge.ok { background: var(--ok-bg); color: var(--ok-border); }
.badge.warn { background: var(--warn-bg); color: #a0741a; }

.status-line { font-size: 13px; color: var(--muted); margin: 8px 0 0; min-height: 20px; }
.color-row { display: flex; gap: 18px; margin-top: 12px; flex-wrap: wrap; }
.color-swatch { text-align: center; }
.color-swatch .swatch {
  width: 72px;
  height: 48px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: repeating-conic-gradient(#eef2f6 0 25%, #fff 0 50%) 50% / 12px 12px;
}
.color-swatch .swatch-label { font-size: 12px; color: var(--muted); margin-top: 4px; }
.color-swatch .swatch-label { font-size: 12px; color: var(--muted); margin-top: 4px; }
.gamut-note {
  font-size: 11px;
  color: #b8860b;
  margin-top: 3px;
  max-width: 96px;
  line-height: 1.3;
}
.overlay-row { margin-top: 14px; }
.overlay-label { font-size: 12px; color: var(--muted); margin: 6px 0 3px; }
.overlay-bar {
  width: 100%;
  max-width: 460px;
  height: 56px;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: #fff;
  display: block;
}
.heatmap-canvas { max-width: 640px; }
.radio-inline { display: inline-flex; align-items: center; gap: 4px; margin-left: 10px; font-size: 13px; color: var(--muted); cursor: pointer; }
.feature-list { margin: 10px 0 4px; padding-left: 22px; }
.feature-list li { margin-bottom: 7px; line-height: 1.55; }
.profile-preview { max-width: 320px; background: #fff; cursor: crosshair; }
.error-box {
  background: #fdecea;
  border: 1px solid #e0a09a;
  color: #92251b;
  border-radius: var(--radius);
  padding: 10px 14px;
  font-size: 13.5px;
  margin-top: 10px;
  display: none;
}

/* ---------------- hero (index) ---------------- */
.hero {
  background: linear-gradient(135deg, #10243a 0%, #123d63 55%, #0b6bcb 100%);
  color: #fff;
  border-radius: 12px;
  padding: 46px 42px;
  margin-bottom: 26px;
}
.hero h1 { font-size: 32px; margin: 0 0 12px; }
.hero p { font-size: 16px; max-width: 760px; color: #d4e2f0; margin: 0 0 22px; }
.hero .btn { font-size: 15px; padding: 12px 26px; }

/* ---------------- docs ---------------- */
.docs-toc { background: #eef3f8; border-radius: var(--radius); padding: 14px 20px; margin-bottom: 18px; }
.docs-toc a { margin-right: 18px; font-weight: 600; font-size: 14px; }
.formula {
  background: var(--code-bg);
  border-left: 3px solid var(--primary);
  padding: 10px 16px;
  margin: 12px 0;
  border-radius: 0 6px 6px 0;
  font-family: Consolas, "Courier New", monospace;
  font-size: 13.5px;
  overflow-x: auto;
  white-space: pre;
}

/* ---------------- footer ---------------- */
footer {
  border-top: 1px solid var(--border);
  margin-top: 40px;
  padding: 18px 20px 30px;
  color: var(--muted);
  font-size: 13px;
  text-align: center;
}

@media (max-width: 760px) {
  .grid-2, .grid-3 { grid-template-columns: 1fr; }
  .hero { padding: 30px 22px; }
  .hero h1 { font-size: 24px; }
  .form-row, .form-row-3 { grid-template-columns: 1fr; }
}