* {
  box-sizing: border-box;
}

:root {
  --bg: #0f172a;
  --card: #111827;
  --accent: #22d3ee;
  --accent-2: #a855f7;
  --text: #e2e8f0;
  --muted: #94a3b8;
  --border: #1f2937;
  --surface: #0b1222;
  --font-body: "Manrope", "Segoe UI", "Helvetica Neue", sans-serif;
}

body {
  margin: 0;
  background: radial-gradient(circle at 20% 20%, rgba(34, 211, 238, 0.12), transparent 30%),
    radial-gradient(circle at 80% 10%, rgba(168, 85, 247, 0.12), transparent 28%),
    var(--bg);
  color: var(--text);
  font-family: var(--font-body);
  line-height: 1.6;
  min-height: 100vh;
}

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

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

header {
  position: sticky;
  top: 0;
  z-index: 10;
  backdrop-filter: blur(10px);
  background: rgba(15, 23, 42, 0.8);
  border-bottom: 1px solid var(--border);
}

.nav {
  max-width: 1200px;
  margin: 0 auto;
  padding: 16px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--accent);
}

.brand span {
  color: var(--text);
}

.nav-links {
  display: flex;
  gap: 16px;
  align-items: center;
}

.nav-links a {
  font-weight: 600;
  padding: 8px 12px;
  border-radius: 10px;
  border: 1px solid transparent;
}

.nav-links a:hover {
  border-color: var(--border);
  background: rgba(255, 255, 255, 0.04);
}

.nav-btn {
  display: inline-block;
}

.theme-toggle {
  background: transparent;
  border: 1px solid var(--border);
  color: var(--text);
  width: auto;
  padding: 8px 12px;
  border-radius: 10px;
  font-size: 16px;
  cursor: pointer;
  transition: transform 0.2s ease;
}

.theme-toggle:hover {
  transform: scale(1.1);
  border-color: var(--accent);
}

html.dark-mode {
  --bg: #e2e8f0;
  --card: #f1f5f9;
  --accent: #0891b2;
  --accent-2: #7c3aed;
  --text: #1e293b;
  --muted: #64748b;
  --border: #cbd5e1;
  --surface: #f8fafc;
}

html.dark-mode body {
  background: radial-gradient(circle at 20% 20%, rgba(8, 145, 178, 0.12), transparent 30%),
    radial-gradient(circle at 80% 10%, rgba(124, 58, 237, 0.12), transparent 28%),
    var(--bg);
}

main {
  max-width: 1200px;
  margin: 0 auto;
  padding: 32px 20px 60px;
}

.hero {
  margin-top: 10px;
  padding: 24px;
  background: linear-gradient(135deg, rgba(34, 211, 238, 0.08), rgba(168, 85, 247, 0.08));
  border: 1px solid var(--border);
  border-radius: 18px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.25);
}

.hero h1 {
  margin: 0 0 12px;
  font-size: 36px;
  letter-spacing: -0.03em;
}

.hero p {
  margin: 0 0 16px;
  color: var(--muted);
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px;
  margin: 24px 0 32px;
}

.card {
  padding: 18px;
  background: var(--card);
  border: 1px solid var(--border);
  border-radius: 14px;
  transition: transform 0.15s ease, border-color 0.15s ease;
}

.card:hover {
  transform: translateY(-4px);
  border-color: rgba(34, 211, 238, 0.6);
}

.card h3 {
  margin: 0 0 8px;
  font-size: 18px;
}

.card p {
  margin: 0;
  color: var(--muted);
}

.section {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 18px;
  padding: 24px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2);
}

.section h2 {
  margin-top: 0;
  margin-bottom: 10px;
  letter-spacing: -0.01em;
}

.section h3 {
  margin-bottom: 6px;
  margin-top: 18px;
}

.section p {
  margin: 0 0 12px;
  color: var(--muted);
}

.section ul {
  margin: 0 0 14px 18px;
  color: var(--muted);
}

footer {
  max-width: 1200px;
  margin: 0 auto;
  padding: 20px;
  color: var(--muted);
  text-align: center;
  border-top: 1px solid var(--border);
}

.tool-shell {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  padding: 20px;
  margin-bottom: 22px;
}

.tool-shell h2 {
  margin-top: 0;
}

.label {
  display: block;
  margin: 10px 0 4px;
  font-weight: 600;
}

textarea,
input,
select,
button {
  width: 100%;
  padding: 12px;
  border-radius: 12px;
  border: 1px solid var(--border);
  background: #0c1425;
  color: var(--text);
  font-family: var(--font-body);
}

button {
  width: auto;
  padding: 12px 16px;
  border: 1px solid transparent;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  color: #0b1222;
  font-weight: 800;
  cursor: pointer;
}

button:hover {
  filter: brightness(1.05);
}

button:focus-visible,
input:focus-visible,
textarea:focus-visible,
select:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.inline-controls {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  align-items: center;
}

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

.stack {
  display: flex;
  flex-direction: column;
}

.small-input {
  max-width: 120px;
}

.result-box {
  margin-top: 10px;
  padding: 12px;
  background: #0c1425;
  border: 1px dashed var(--border);
  border-radius: 12px;
  min-height: 48px;
  word-break: break-word;
}

.muted-text {
  color: var(--muted);
  font-size: 14px;
}

.meter {
  margin-top: 10px;
  background: #0c1425;
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
  height: 12px;
}

.meter-fill {
  height: 100%;
  width: 0;
  background: linear-gradient(90deg, #f87171, #fbbf24, #34d399, #22d3ee);
  transition: width 0.2s ease;
}

.history-list {
  display: grid;
  gap: 8px;
}

.history-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 12px;
  background: #0c1425;
  border: 1px solid var(--border);
  border-radius: 10px;
  font-size: 14px;
  gap: 12px;
}

.history-value {
  flex: 1;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

.pill {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 6px 10px;
  border-radius: 999px;
  background: rgba(226, 232, 240, 0.05);
  border: 1px solid var(--border);
  font-size: 13px;
  color: var(--text);
}

.badge {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 8px;
  border: 1px solid var(--border);
  background: rgba(34, 211, 238, 0.12);
  font-size: 12px;
  color: var(--text);
}

.status-good { color: #34d399; }
.status-warn { color: #fbbf24; }
.status-bad { color: #f87171; }

.table {
  width: 100%;
  border-collapse: collapse;
  background: #0c1425;
  border: 1px solid var(--border);
  border-radius: 12px;
  overflow: hidden;
}

.table th,
.table td {
  padding: 10px;
  border-bottom: 1px solid var(--border);
  text-align: left;
  font-size: 14px;
}

.table tr:last-child td { border-bottom: none; }

.muted-bg {
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 12px;
}

.tag {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 999px;
  background: rgba(34, 211, 238, 0.12);
  border: 1px solid var(--border);
  color: var(--text);
  font-size: 12px;
  margin-left: 6px;
}

.two-col {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 12px;
  width: 100%;
}

.gradient-preview {
  height: 200px;
  border-radius: 12px;
  border: 1px solid var(--border);
  margin-top: 12px;
}

.toast-host {
  position: fixed;
  bottom: 20px;
  right: 20px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  z-index: 50;
}

.toast {
  padding: 12px 14px;
  border-radius: 10px;
  background: rgba(17, 24, 39, 0.95);
  border: 1px solid var(--border);
  color: var(--text);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.35);
  opacity: 0;
  transform: translateY(10px);
  transition: opacity 0.2s ease, transform 0.2s ease;
}

.toast-success { border-color: rgba(34, 211, 238, 0.6); }
.toast-error { border-color: #f87171; }
.toast.show { opacity: 1; transform: translateY(0); }

.update-banner {
  position: fixed;
  bottom: 20px;
  left: 20px;
  right: 20px;
  max-width: 420px;
  margin: 0 auto;
  padding: 12px 14px;
  background: #0c1425;
  border: 1px solid var(--border);
  border-radius: 12px;
  box-shadow: 0 12px 30px rgba(0, 0, 0, 0.35);
  display: flex;
  align-items: center;
  gap: 10px;
  z-index: 60;
}

.update-banner button {
  margin-left: auto;
}

@media (max-width: 640px) {
  .nav {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
  }

  .nav-links {
    flex-wrap: wrap;
    gap: 10px;
  }

  .hero h1 {
    font-size: 30px;
  }
}