:root {
  --bg: #0d1117;
  --surface: #161b22;
  --surface2: #21262d;
  --border: #30363d;
  --text: #c9d1d9;
  --text-muted: #8b949e;
  --accent: #58a6ff;
  --accent-hover: #79b8ff;
  --success: #3fb950;
  --error: #f85149;
  --warning: #d29922;
  --radius: 8px;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Cascadia Code', 'Consolas', monospace;
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--font-sans);
  font-size: 15px;
  line-height: 1.6;
  min-height: 100vh;
}

/* ── Nav ── */
nav {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  padding: 0 20px;
  display: flex;
  align-items: center;
  gap: 16px;
  height: 52px;
  position: sticky;
  top: 0;
  z-index: 100;
}

.nav-logo {
  font-weight: 700;
  font-size: 16px;
  color: var(--accent);
  text-decoration: none;
  letter-spacing: -0.3px;
  white-space: nowrap;
}

.nav-logo span { color: var(--text-muted); font-weight: 400; }

.nav-links {
  display: flex;
  gap: 4px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
}

.nav-links::-webkit-scrollbar { display: none; }

.nav-links a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 13px;
  padding: 6px 10px;
  border-radius: var(--radius);
  white-space: nowrap;
  transition: color .15s, background .15s;
}

.nav-links a:hover, .nav-links a.active {
  color: var(--text);
  background: var(--surface2);
}

/* ── Layout ── */
.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 32px 20px 64px;
}

.page-header {
  margin-bottom: 28px;
}

.page-header h1 {
  font-size: 22px;
  font-weight: 700;
  letter-spacing: -0.4px;
  margin-bottom: 6px;
}

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

/* ── Tool card ── */
.tool-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 20px;
  margin-bottom: 16px;
}

.tool-card h2 {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: .5px;
  margin-bottom: 12px;
}

/* ── Inputs & Textareas ── */
textarea, input[type=text], input[type=number], select {
  width: 100%;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: var(--text);
  font-family: var(--font-mono);
  font-size: 13px;
  padding: 12px 14px;
  outline: none;
  resize: vertical;
  transition: border-color .15s;
}

textarea:focus, input:focus, select:focus {
  border-color: var(--accent);
}

textarea { min-height: 180px; }

select { resize: none; cursor: pointer; }

/* ── Buttons ── */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  border-radius: var(--radius);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: background .15s, transform .1s;
  user-select: none;
}

.btn:active { transform: scale(.97); }

.btn-primary {
  background: var(--accent);
  color: #0d1117;
}

.btn-primary:hover { background: var(--accent-hover); }

.btn-secondary {
  background: var(--surface2);
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-secondary:hover { background: var(--border); }

.btn-success {
  background: var(--success);
  color: #0d1117;
}

.btn-row {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
  margin-top: 12px;
}

/* ── Output area ── */
.output-wrapper {
  position: relative;
  margin-top: 16px;
}

.output-label {
  font-size: 12px;
  color: var(--text-muted);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: .4px;
  margin-bottom: 8px;
}

.output {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 14px;
  font-family: var(--font-mono);
  font-size: 13px;
  overflow-x: auto;
  white-space: pre-wrap;
  word-break: break-word;
  min-height: 120px;
  max-height: 500px;
  overflow-y: auto;
}

.copy-btn {
  position: absolute;
  top: 34px;
  right: 8px;
  background: var(--surface2);
  border: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 12px;
  padding: 4px 10px;
  border-radius: 6px;
  cursor: pointer;
  transition: all .15s;
}

.copy-btn:hover { color: var(--text); border-color: var(--accent); }
.copy-btn.copied { color: var(--success); border-color: var(--success); }

/* ── Grid ── */
.two-col {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

@media (max-width: 680px) {
  .two-col { grid-template-columns: 1fr; }
  nav { padding: 0 12px; }
  .container { padding: 20px 12px 48px; }
}

/* ── Status badges ── */
.badge {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-size: 12px;
  padding: 3px 9px;
  border-radius: 20px;
  font-weight: 600;
}

.badge-success { background: rgba(63,185,80,.15); color: var(--success); }
.badge-error   { background: rgba(248,81,73,.15);  color: var(--error); }
.badge-warn    { background: rgba(210,153,34,.15);  color: var(--warning); }

/* ── Info box ── */
.info-box {
  background: rgba(88,166,255,.08);
  border: 1px solid rgba(88,166,255,.2);
  border-radius: var(--radius);
  padding: 12px 16px;
  font-size: 13px;
  color: var(--text-muted);
  margin-top: 12px;
}

.info-box strong { color: var(--accent); }

/* ── Index grid ── */
.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 12px;
}

.tool-item {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 18px;
  text-decoration: none;
  color: var(--text);
  transition: border-color .15s, transform .15s;
  display: block;
}

.tool-item:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
}

.tool-item-icon { font-size: 24px; margin-bottom: 10px; }

.tool-item-title {
  font-size: 14px;
  font-weight: 700;
  margin-bottom: 4px;
}

.tool-item-desc {
  font-size: 12px;
  color: var(--text-muted);
  line-height: 1.5;
}

/* ── Tabs ── */
.tabs {
  display: flex;
  gap: 4px;
  border-bottom: 1px solid var(--border);
  margin-bottom: 16px;
}

.tab {
  padding: 8px 14px;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  border-radius: var(--radius) var(--radius) 0 0;
  color: var(--text-muted);
  border: 1px solid transparent;
  border-bottom: none;
  background: none;
  transition: all .15s;
}

.tab.active {
  color: var(--accent);
  background: var(--surface);
  border-color: var(--border);
  border-bottom-color: var(--surface);
  margin-bottom: -1px;
}

/* ── Range input ── */
input[type=range] {
  width: 100%;
  accent-color: var(--accent);
  height: 4px;
  border: none;
  padding: 0;
  background: transparent;
}

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

footer a { color: var(--accent); text-decoration: none; }