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

:root {
  --bg: #f4f6f9;
  --card-bg: #ffffff;
  --text: #1a1a2e;
  --text-muted: #6b7280;
  --border: #d1d5db;
  --accent: #2563eb;
  --accent-hover: #1d4ed8;
  --danger: #dc2626;
  --danger-bg: #fef2f2;
  --danger-border: #fecaca;
  --danger-text: #991b1b;
  --warning: #d97706;
  --warning-bg: #fffbeb;
  --warning-border: #fde68a;
  --warning-text: #92400e;
  --info-bg: #eff6ff;
  --info-border: #bfdbfe;
  --info-text: #1e40af;
  --success: #16a34a;
  --hover-bg: #f9fafb;
  --bar-bg: #e5e7eb;
  --radius: 8px;
  --radius-lg: 12px;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.08), 0 1px 2px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 4px 6px rgba(0, 0, 0, 0.07), 0 10px 15px rgba(0, 0, 0, 0.05);
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --font-mono: "SF Mono", "Fira Code", "Fira Mono", "Roboto Mono", monospace;
  --breakdown-text: #ffffff;
}

[data-theme="dark"] {
  --bg: #0f172a;
  --card-bg: #1e293b;
  --text: #e2e8f0;
  --text-muted: #94a3b8;
  --border: #334155;
  --accent: #3b82f6;
  --accent-hover: #60a5fa;
  --danger: #ef4444;
  --danger-bg: #451a1a;
  --danger-border: #7f1d1d;
  --danger-text: #fca5a5;
  --warning: #f59e0b;
  --warning-bg: #451a03;
  --warning-border: #78350f;
  --warning-text: #fcd34d;
  --info-bg: #1e3a5f;
  --info-border: #1e40af;
  --info-text: #93c5fd;
  --success: #22c55e;
  --hover-bg: #334155;
  --bar-bg: #334155;
  --shadow: 0 1px 3px rgba(0, 0, 0, 0.3), 0 1px 2px rgba(0, 0, 0, 0.2);
  --shadow-lg: 0 4px 6px rgba(0, 0, 0, 0.25), 0 10px 15px rgba(0, 0, 0, 0.2);
  --breakdown-text: #f8fafc;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.5;
  padding: 24px 16px;
  min-height: 100vh;
  transition: background 0.2s, color 0.2s;
}

.container {
  max-width: 960px;
  margin: 0 auto;
}

header {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  margin-bottom: 24px;
  flex-wrap: wrap;
}

header h1 {
  font-size: 1.75rem;
  font-weight: 700;
  letter-spacing: -0.02em;
}

.subtitle {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-top: 4px;
  width: 100%;
  text-align: center;
}

/* Theme toggle */
.theme-toggle {
  flex-shrink: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border: 1px solid var(--border);
  border-radius: 50%;
  background: var(--card-bg);
  color: var(--text-muted);
  cursor: pointer;
  transition: all 0.15s;
  margin-left: auto;
}

.theme-toggle:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--hover-bg);
}

/* Presets */
.presets {
  margin-bottom: 20px;
}

.preset-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.preset-btn {
  padding: 6px 14px;
  font-size: 0.8rem;
  font-weight: 500;
  border: 1px solid var(--border);
  border-radius: 20px;
  background: var(--card-bg);
  color: var(--text);
  cursor: pointer;
  transition: all 0.15s;
  white-space: nowrap;
}

.preset-btn:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: var(--hover-bg);
}

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

/* Main layout */
.main-layout {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.inputs-card,
.protocols-card,
.results-card {
  background: var(--card-bg);
  border-radius: var(--radius-lg);
  padding: 20px;
  box-shadow: var(--shadow);
  transition: background 0.2s, box-shadow 0.2s;
}

.inputs-card h2,
.protocols-card h2,
.results-card h2 {
  font-size: 1rem;
  font-weight: 600;
  margin-bottom: 12px;
}

.section-note {
  font-size: 0.8rem;
  color: var(--text-muted);
  margin-bottom: 12px;
}

/* Input row */
.input-row {
  display: flex;
  gap: 12px;
  align-items: flex-end;
  flex-wrap: wrap;
}

.input-group {
  flex: 1;
  min-width: 120px;
}

.input-group label {
  display: block;
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--text-muted);
  margin-bottom: 4px;
}

.input-group input {
  width: 100%;
  padding: 8px 12px;
  font-size: 0.95rem;
  font-family: var(--font-mono);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg);
  color: var(--text);
  transition: border-color 0.15s, background 0.2s, color 0.2s;
}

.input-group input:focus {
  outline: none;
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.12);
}

[data-theme="dark"] .input-group input:focus {
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.2);
}

.input-group-btn {
  flex: 0 0 auto;
  min-width: auto;
}

.btn-primary {
  padding: 8px 24px;
  font-size: 0.9rem;
  font-weight: 600;
  border: none;
  border-radius: var(--radius);
  background: var(--accent);
  color: #fff;
  cursor: pointer;
  transition: background 0.15s;
  white-space: nowrap;
}

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

/* Protocol categories */
.protocol-category {
  margin-bottom: 16px;
}

.protocol-category:last-child {
  margin-bottom: 0;
}

.protocol-category h3 {
  font-size: 0.8rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  margin-bottom: 8px;
  padding-bottom: 4px;
  border-bottom: 1px solid var(--border);
}

.protocol-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 5px 0;
  cursor: pointer;
}

.protocol-item:hover {
  background: var(--hover-bg);
  margin: 0 -6px;
  padding: 5px 6px;
  border-radius: 4px;
}

.protocol-item input[type="checkbox"] {
  flex-shrink: 0;
  width: 16px;
  height: 16px;
  accent-color: var(--accent);
  cursor: pointer;
}

.protocol-color-dot {
  flex-shrink: 0;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  display: inline-block;
}

.protocol-name {
  font-size: 0.88rem;
  flex: 1;
}

.protocol-overhead {
  font-size: 0.8rem;
  font-family: var(--font-mono);
  color: var(--text-muted);
  white-space: nowrap;
}

.protocol-count {
  width: 48px;
  padding: 2px 6px;
  font-size: 0.8rem;
  font-family: var(--font-mono);
  border: 1px solid var(--border);
  border-radius: 4px;
  text-align: center;
  background: var(--bg);
  color: var(--text);
  transition: background 0.2s, color 0.2s, border-color 0.2s;
}

.protocol-count:focus {
  outline: none;
  border-color: var(--accent);
}

.protocol-desc {
  font-size: 0.75rem;
  color: var(--text-muted);
  margin-left: 34px;
  margin-top: -2px;
  margin-bottom: 4px;
}

/* Results grid */
.results-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
  gap: 12px;
  margin-bottom: 20px;
}

.result-item {
  background: var(--bg);
  border-radius: var(--radius);
  padding: 12px 14px;
  text-align: center;
}

.result-label {
  display: block;
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--text-muted);
  margin-bottom: 4px;
}

.result-value {
  display: block;
  font-size: 1.3rem;
  font-weight: 700;
  font-family: var(--font-mono);
  color: var(--text);
}

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

/* Breakdown bar */
.breakdown-section {
  margin-bottom: 16px;
}

.breakdown-section h3 {
  font-size: 0.85rem;
  font-weight: 600;
  margin-bottom: 8px;
}

.breakdown-bar {
  display: flex;
  height: 36px;
  border-radius: var(--radius);
  overflow: hidden;
  border: 1px solid var(--border);
  background: var(--bar-bg);
}

.breakdown-segment {
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.6rem;
  font-weight: 600;
  color: var(--breakdown-text);
  text-shadow: 0 1px 2px rgba(0, 0, 0, 0.4);
  transition: flex 0.2s;
  min-width: 2px;
  position: relative;
  overflow: hidden;
}

.breakdown-segment:hover {
  opacity: 0.85;
  cursor: default;
}

.breakdown-segment .seg-label {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  padding: 0 4px;
  font-size: 0.6rem;
}

.breakdown-labels {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 16px;
  margin-top: 8px;
  font-size: 0.78rem;
}

.breakdown-label {
  display: flex;
  align-items: center;
  gap: 5px;
}

.breakdown-label .label-dot {
  width: 10px;
  height: 10px;
  border-radius: 2px;
  flex-shrink: 0;
}

.breakdown-label .label-size {
  font-family: var(--font-mono);
  color: var(--text-muted);
  font-size: 0.72rem;
}

/* Fragmentation info */
.frag-info {
  border-radius: var(--radius);
  padding: 12px 14px;
  font-size: 0.85rem;
  transition: background 0.2s, border-color 0.2s;
}

.frag-info.warning {
  background: var(--warning-bg);
  border: 1px solid var(--warning-border);
  color: var(--warning-text);
}

.frag-info.danger {
  background: var(--danger-bg);
  border: 1px solid var(--danger-border);
  color: var(--danger-text);
}

.frag-info.info {
  background: var(--info-bg);
  border: 1px solid var(--info-border);
  color: var(--info-text);
}

.frag-info.hidden {
  display: none;
}

.frag-info strong {
  display: block;
  margin-bottom: 4px;
}

.frag-info ul {
  margin: 6px 0 0 18px;
}

.frag-info li {
  margin-bottom: 2px;
}

/* Footer */
footer {
  text-align: center;
  margin-top: 24px;
  font-size: 0.78rem;
  color: var(--text-muted);
}

/* Responsive */
@media (min-width: 768px) {
  body {
    padding: 32px 24px;
  }

  .main-layout {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
  }

  .inputs-card {
    grid-column: 1 / -1;
  }

  .results-card {
    grid-column: 1 / -1;
  }
}

@media (min-width: 1024px) {
  .main-layout {
    grid-template-columns: 1fr 1fr;
  }

  .inputs-card {
    grid-column: 1 / -1;
  }

  .results-card {
    grid-column: 1 / -1;
  }

  .input-row {
    flex-wrap: nowrap;
  }
}