/* ===== Reset & Base ===== */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* ===== Light Theme (default) ===== */
:root {
    --blue: #2563EB;
    --blue-light: #EBF2FF;
    --blue-hover: #1D4ED8;
    --bg: #F3F4F6;
    --card: #FFFFFF;
    --sidebar-bg: #FFFFFF;
    --text: #1A1A2E;
    --text-secondary: #6B7280;
    --text-muted: #9CA3AF;
    --border: #E5E7EB;
    --input-bg: #F3F4F6;
    --code-bg: #F3F4F6;
    --sidebar-width: 260px;
    --topbar-height: 60px;
    --radius: 12px;
    --radius-sm: 8px;
    --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.04);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.06), 0 2px 4px rgba(0,0,0,0.04);
}

/* ===== Dark Theme ===== */
[data-theme="dark"] {
    --bg: #0F172A;
    --card: #1E293B;
    --sidebar-bg: #1E293B;
    --text: #E2E8F0;
    --text-secondary: #94A3B8;
    --text-muted: #64748B;
    --border: #334155;
    --blue-light: #1E3A5F;
    --input-bg: #0F172A;
    --code-bg: #0F172A;
    --shadow: 0 1px 3px rgba(0,0,0,0.3);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.4);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Inter', Roboto, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.5;
    min-height: 100vh;
    transition: background 0.3s, color 0.3s;
}

a { color: inherit; text-decoration: none; }
button { cursor: pointer; border: none; background: none; font-family: inherit; color: inherit; }

/* ===== Sidebar ===== */
.sidebar {
    position: fixed;
    top: 0;
    left: 0;
    width: var(--sidebar-width);
    height: 100vh;
    background: var(--sidebar-bg);
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    z-index: 100;
    padding: 24px 16px 16px;
    overflow-y: auto;
    transition: background 0.3s, border-color 0.3s;
    scrollbar-color: rgba(148, 163, 184, 0.4) transparent;
    scrollbar-width: thin;
}

.sidebar::-webkit-scrollbar { width: 6px; }
.sidebar::-webkit-scrollbar-track { background: transparent; }
.sidebar::-webkit-scrollbar-thumb {
    background: rgba(148, 163, 184, 0.4);
    border-radius: 3px;
}
.sidebar::-webkit-scrollbar-thumb:hover { background: rgba(148, 163, 184, 0.6); }

.sidebar-logo { margin-bottom: 24px; }

.sidebar-logo-link {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 0 8px;
}

.logo-icon {
    width: 40px;
    height: 40px;
    background: rgba(37, 99, 235, 0.12);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    border: 1px solid rgba(37, 99, 235, 0.2);
}

.logo-img {
    width: 26px;
    height: 26px;
    display: block;
}

[data-theme="dark"] .logo-icon {
    background: rgba(59, 130, 246, 0.2);
    border-color: rgba(96, 165, 250, 0.5);
}

[data-theme="dark"] .logo-img {
    filter: brightness(0) saturate(100%) invert(1);
    opacity: 0.95;
}

.logo-name { display: block; font-weight: 700; font-size: 16px; color: var(--text); }
.logo-sub { display: block; font-size: 12px; color: var(--text-muted); }

/* Sidebar Search */
.sidebar-search { position: relative; margin-bottom: 20px; }

.sidebar-search input {
    width: 100%;
    padding: 10px 12px 10px 36px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 13px;
    color: var(--text);
    background: var(--input-bg);
    outline: none;
    transition: border-color 0.2s, background 0.3s;
}

.sidebar-search input:focus { border-color: var(--blue); }

.search-icon {
    position: absolute;
    left: 12px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
}

/* Sidebar Nav Groups */
.sidebar-nav { display: flex; flex-direction: column; gap: 4px; }

.nav-group-toggle {
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
    padding: 10px 8px 6px;
    background: none;
    border: none;
    cursor: pointer;
}

.nav-group-label {
    font-size: 11px;
    font-weight: 600;
    color: var(--text-muted);
    letter-spacing: 0.05em;
}

.nav-group-toggle .chevron {
    color: var(--text-muted);
    transition: transform 0.2s;
    width: 14px;
    height: 14px;
}

.nav-group-toggle.open .chevron { transform: rotate(90deg); }

.nav-group-items {
    display: flex;
    flex-direction: column;
    gap: 1px;
    padding-left: 4px;
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    transition: max-height 0.25s ease, opacity 0.2s ease;
}

.nav-group-items.open {
    max-height: 520px;
    opacity: 1;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 12px;
    border-radius: var(--radius-sm);
    font-size: 13.5px;
    color: var(--text-secondary);
    transition: all 0.15s;
    white-space: nowrap;
}

.nav-item:hover { background: var(--input-bg); color: var(--text); }
.nav-item.active { background: var(--blue-light); color: var(--blue); font-weight: 600; }
.nav-item.hidden { display: none; }
.nav-item svg { flex-shrink: 0; }

.sidebar-bottom {
    display: flex;
    flex-direction: column;
    gap: 2px;
    border-top: 1px solid var(--border);
    padding-top: 12px;
    flex-shrink: 0;
}

/* Dark mode toggle */
.theme-toggle-btn { position: relative; }
[data-theme="dark"] .theme-icon-light { display: none; }
.theme-icon-dark { display: none; }
[data-theme="dark"] .theme-icon-dark { display: block; }

/* Sidebar overlay for mobile */
.sidebar-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.5);
    z-index: 99;
}

.sidebar-overlay.open { display: block; }

/* ===== Main Wrapper ===== */
.main-wrapper {
    margin-left: var(--sidebar-width);
    min-height: 100vh;
    transition: margin-left 0.3s;
}

/* ===== Top Bar ===== */
.topbar {
    height: var(--topbar-height);
    background: var(--card);
    border-bottom: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 32px;
    position: sticky;
    top: 0;
    z-index: 50;
    transition: background 0.3s, border-color 0.3s;
}

.topbar-left { display: flex; align-items: center; gap: 12px; }

.mobile-menu-btn {
    display: none;
    width: 40px;
    height: 40px;
    align-items: center;
    justify-content: center;
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
}

.breadcrumb { display: flex; align-items: center; gap: 8px; font-size: 14px; }
.breadcrumb-link { color: var(--text-muted); transition: color 0.15s; }
.breadcrumb-link:hover { color: var(--blue); }
.breadcrumb svg { color: var(--text-muted); }
.breadcrumb-current { color: var(--text); font-weight: 600; }

/* ===== Content ===== */
.content { padding: 36px; max-width: 980px; }
.page-header { margin-bottom: 20px; }
.page-header h1 { font-size: 30px; font-weight: 700; color: var(--text); letter-spacing: -0.01em; }
.page-subtitle { color: var(--text-secondary); font-size: 15.5px; margin-top: 6px; }
.section-title { font-size: 18px; font-weight: 700; margin-top: 32px; margin-bottom: 4px; color: var(--text); }

/* ===== Category Header ===== */
.category-header {
    display: flex;
    align-items: center;
    gap: 16px;
    background: var(--card);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 16px 20px;
    margin-bottom: 18px;
}

.category-header-icon {
    width: 44px;
    height: 44px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, rgba(37,99,235,0.16), rgba(37,99,235,0.04));
    color: var(--blue);
}

.category-header-icon svg { width: 22px; height: 22px; }
.category-header-icon .icon-mask { width: 22px; height: 22px; }

.category-header-text h2 {
    font-size: 18px;
    font-weight: 700;
    color: var(--text);
    margin-bottom: 2px;
}

.category-header-text p {
    font-size: 13px;
    color: var(--text-secondary);
}

.category-header-actions {
    margin-left: auto;
    display: flex;
    align-items: center;
    gap: 8px;
}

.precision-label {
    font-size: 12px;
    color: var(--text-muted);
    font-weight: 600;
    letter-spacing: 0.03em;
}

.precision-select {
    padding: 6px 10px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 12.5px;
    background: var(--input-bg);
    color: var(--text);
}

/* ===== Convert Card ===== */
.convert-card {
    background: var(--card);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    overflow: visible;
    transition: background 0.3s, box-shadow 0.3s;
}

.convert-category-bar {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 16px 32px 0;
}

.convert-category-label {
    font-size: 12px;
    font-weight: 600;
    color: var(--text-muted);
    letter-spacing: 0.03em;
}

.convert-category-select {
    padding: 6px 12px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 13px;
    color: var(--text);
    background: var(--input-bg);
    outline: none;
    cursor: pointer;
    transition: background 0.3s, border-color 0.3s, color 0.3s;
}

.convert-body {
    display: flex;
    align-items: flex-start;
    padding: 26px 32px 22px;
    gap: 22px;
}

.convert-side { flex: 1; min-width: 0; }

.convert-label {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 11px;
    font-weight: 600;
    color: var(--text-muted);
    letter-spacing: 0.05em;
    margin-bottom: 8px;
}

.convert-dot { width: 8px; height: 8px; background: var(--blue); border-radius: 50%; }

.convert-input {
    width: 100%;
    font-size: 32px;
    font-weight: 700;
    color: var(--text);
    border: 1px solid var(--border);
    outline: none;
    padding: 10px 14px;
    background: var(--input-bg);
    border-radius: var(--radius-sm);
    box-shadow: inset 0 1px 2px rgba(15, 23, 42, 0.12);
    margin-bottom: 12px;
    -moz-appearance: textfield;
}

.convert-input::-webkit-outer-spin-button,
.convert-input::-webkit-inner-spin-button { -webkit-appearance: none; margin: 0; }

.convert-result {
    font-size: 32px;
    font-weight: 700;
    color: var(--blue);
    margin-bottom: 12px;
    min-height: 48px;
    display: flex;
    align-items: center;
    word-break: break-all;
}

.convert-select {
    width: 100%;
    padding: 10px 14px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 14px;
    color: var(--text);
    background: var(--card);
    outline: none;
    cursor: pointer;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%236B7280' stroke-width='2' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 12px center;
    transition: background 0.3s, border-color 0.3s, color 0.3s;
}

.convert-select:focus { border-color: var(--blue); }

.convert-to-header { display: flex; justify-content: space-between; align-items: center; }
.convert-to-actions { display: flex; gap: 4px; }

/* Unit dropdown */
.unit-dropdown {
    position: relative;
}

.unit-dropdown .convert-select {
    position: absolute;
    opacity: 0;
    pointer-events: none;
    height: 0;
}

.unit-dropdown-toggle {
    width: 100%;
    padding: 10px 36px 10px 14px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 14px;
    color: var(--text);
    background: var(--card);
    text-align: left;
    cursor: pointer;
    transition: border-color 0.2s, background 0.2s, box-shadow 0.2s;
    background-image: url("data:image/svg+xml,%3Csvg width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%236B7280' stroke-width='2' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 12px center;
}

.unit-dropdown-toggle:focus {
    outline: none;
    border-color: var(--blue);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.15);
}

.unit-dropdown.open .unit-dropdown-toggle {
    border-color: var(--blue);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

.unit-dropdown-panel {
    position: absolute;
    top: calc(100% + 8px);
    left: 0;
    right: 0;
    background: var(--card);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    box-shadow: var(--shadow-md);
    padding: 10px;
    display: none;
    z-index: 20;
}

.unit-dropdown.open .unit-dropdown-panel { display: block; }

.unit-dropdown-search {
    width: 100%;
    padding: 8px 10px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 13px;
    background: var(--input-bg);
    color: var(--text);
    outline: none;
    margin-bottom: 8px;
}

.unit-dropdown-list {
    max-height: 320px;
    overflow: auto;
    display: flex;
    flex-direction: column;
    gap: 2px;
    scrollbar-color: rgba(148, 163, 184, 0.6) transparent;
    scrollbar-width: thin;
}

.unit-dropdown-list::-webkit-scrollbar { width: 10px; }
.unit-dropdown-list::-webkit-scrollbar-track { background: transparent; }
.unit-dropdown-list::-webkit-scrollbar-thumb {
    background: rgba(148, 163, 184, 0.4);
    border-radius: 999px;
    border: 2px solid transparent;
    background-clip: padding-box;
}
.unit-dropdown-list::-webkit-scrollbar-thumb:hover { background: rgba(148, 163, 184, 0.65); }

.unit-option {
    padding: 8px 10px;
    border-radius: 6px;
    font-size: 13.5px;
    color: var(--text);
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    gap: 12px;
}

.unit-option:hover,
.unit-option.active { background: var(--input-bg); }

.unit-option.hidden { display: none; }

.unit-option-value { color: var(--text-secondary); font-variant-numeric: tabular-nums; }

.icon-btn-sm {
    width: 28px;
    height: 28px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 6px;
    color: var(--text-muted);
    transition: all 0.15s;
}

.icon-btn-sm:hover { background: var(--input-bg); color: var(--text); }
.icon-btn-sm.copied { color: #10B981; }

/* Tooltip */
[data-tooltip] {
    position: relative;
}

[data-tooltip]::after {
    content: attr(data-tooltip);
    position: absolute;
    bottom: calc(100% + 8px);
    left: 50%;
    transform: translateX(-50%) translateY(4px);
    background: var(--card);
    color: var(--text);
    font-size: 11.5px;
    padding: 6px 8px;
    border-radius: 6px;
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
    opacity: 0;
    pointer-events: none;
    white-space: nowrap;
    transition: opacity 0.12s ease, transform 0.12s ease;
    z-index: 40;
}

[data-tooltip]:hover::after,
[data-tooltip]:focus-visible::after {
    opacity: 1;
    transform: translateX(-50%) translateY(0);
}

/* Swap Button */
.swap-btn {
    width: 48px;
    height: 48px;
    min-width: 48px;
    background: var(--blue);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    transition: all 0.2s;
    margin-top: 40px;
    box-shadow: 0 2px 8px rgba(37, 99, 235, 0.3);
}

.swap-btn:hover { background: var(--blue-hover); transform: scale(1.05); }
.swap-btn:active { transform: scale(0.95); }

/* Convert Meta */
.convert-meta {
    padding: 0 32px 16px;
    display: flex;
    gap: 24px;
    flex-wrap: wrap;
}

.meta-text { font-size: 13px; color: var(--text-muted); }
.meta-formula { font-size: 13px; color: var(--text-muted); font-style: italic; }
.meta-sources { font-size: 12px; color: var(--text-muted); }

/* ===== Recent Conversions ===== */
.recent-section { margin-top: 32px; }

.recent-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 16px;
}

.recent-header h2 { font-size: 18px; font-weight: 700; }

.clear-link {
    font-size: 13px;
    color: var(--blue);
    font-weight: 500;
    background: none;
    border: none;
    cursor: pointer;
}

.clear-link:hover { text-decoration: underline; }

.recent-list {
    background: var(--card);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    overflow: hidden;
    transition: background 0.3s;
}

.recent-empty {
    padding: 24px;
    text-align: center;
    color: var(--text-muted);
    font-size: 14px;
}

.recent-item {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 14px 24px;
    border-bottom: 1px solid var(--border);
    transition: background 0.1s;
}

.recent-item:last-child { border-bottom: none; }
.recent-item:hover { background: var(--input-bg); }

.recent-icon {
    width: 38px;
    height: 38px;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    font-size: 16px;
    background: var(--blue-light);
    color: var(--blue);
}

.recent-info { display: flex; flex-direction: column; min-width: 0; }
.recent-conversion { font-size: 14px; font-weight: 600; color: var(--text); }
.recent-meta { font-size: 12px; color: var(--text-muted); margin-top: 2px; }

/* ===== Recent Categories ===== */
.recent-categories {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.recent-category-item {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 8px 12px;
    border-radius: 999px;
    border: 1px solid var(--border);
    background: var(--card);
    color: var(--text);
    font-size: 13px;
    font-weight: 600;
    transition: background 0.15s, border-color 0.15s, color 0.15s;
}

.recent-category-item:hover {
    background: var(--input-bg);
    border-color: rgba(37, 99, 235, 0.25);
    color: var(--blue);
}

/* ===== Category Cards ===== */
.category-cards {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 16px;
    margin-top: 16px;
}

.category-card {
    background: var(--card);
    border-radius: var(--radius);
    padding: 20px;
    box-shadow: var(--shadow);
    border: 1px solid transparent;
    transition: box-shadow 0.2s, transform 0.2s, background 0.3s, border-color 0.2s;
    cursor: pointer;
    display: block;
}

.category-card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
    border-color: rgba(37, 99, 235, 0.25);
}

.category-card-header { display: flex; align-items: center; gap: 12px; }
.category-card-header h3 { font-size: 15px; font-weight: 700; color: var(--text); }

.category-card-icon {
    width: 38px;
    height: 38px;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    background: linear-gradient(135deg, rgba(37,99,235,0.18), rgba(37,99,235,0.05));
    color: var(--blue);
}

.category-card-icon svg { width: 18px; height: 18px; }
.category-card-icon .icon-mask { width: 18px; height: 18px; }

.icon-mask {
    background-color: currentColor;
    -webkit-mask-size: contain;
    mask-size: contain;
    -webkit-mask-repeat: no-repeat;
    mask-repeat: no-repeat;
    -webkit-mask-position: center;
    mask-position: center;
}

/* ===== Converter Groups ===== */
.converter-groups {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-top: 12px;
}

.converter-group {
    background: var(--card);
    border-radius: var(--radius);
    border: 1px solid var(--border);
    overflow: hidden;
    box-shadow: var(--shadow);
}

.converter-group-toggle {
    width: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    padding: 14px 18px;
    background: var(--input-bg);
    border: none;
    cursor: pointer;
}

.converter-group-title {
    font-size: 16px;
    font-weight: 700;
    color: var(--text);
}

.converter-group-toggle .chevron {
    width: 18px;
    height: 18px;
    color: var(--text-muted);
    transition: transform 0.2s;
}

.converter-group-toggle.open .chevron { transform: rotate(90deg); }

.converter-group-body {
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    padding: 12px 18px 16px;
    transition: max-height 0.3s ease, opacity 0.2s ease;
}

.converter-group-body.open {
    max-height: 520px;
    opacity: 1;
}

.converter-group-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(160px, 1fr));
    gap: 8px 24px;
}

.converter-group-link {
    color: var(--text);
    font-weight: 600;
    padding: 6px 8px;
    border-radius: var(--radius-sm);
    transition: background 0.15s, color 0.15s;
}

.converter-group-link:hover {
    background: var(--input-bg);
    color: var(--blue);
}

/* ===== API Docs ===== */
.docs-section { margin-bottom: 24px; }
.docs-intro { font-size: 15px; color: var(--text-secondary); }

.code-inline {
    background: var(--code-bg);
    padding: 2px 6px;
    border-radius: 4px;
    font-family: 'SF Mono', 'Fira Code', monospace;
    font-size: 13px;
    color: var(--blue);
}

.docs-card {
    background: var(--card);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 28px 32px;
    margin-bottom: 24px;
    transition: background 0.3s;
}

.docs-card h2 {
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 20px;
    color: var(--text);
}

.endpoint { margin-bottom: 32px; padding-bottom: 32px; border-bottom: 1px solid var(--border); }
.endpoint:last-child { margin-bottom: 0; padding-bottom: 0; border-bottom: none; }

.endpoint-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 10px;
}

.endpoint-header code {
    font-family: 'SF Mono', 'Fira Code', monospace;
    font-size: 15px;
    font-weight: 600;
    color: var(--text);
}

.method {
    display: inline-block;
    padding: 3px 10px;
    border-radius: 4px;
    font-size: 12px;
    font-weight: 700;
    letter-spacing: 0.03em;
}

.method.get { background: #D1FAE5; color: #065F46; }
[data-theme="dark"] .method.get { background: #064E3B; color: #6EE7B7; }
.method.post { background: #DBEAFE; color: #1D4ED8; }
[data-theme="dark"] .method.post { background: #1E3A8A; color: #93C5FD; }

.endpoint p { color: var(--text-secondary); margin-bottom: 16px; font-size: 14px; }
.endpoint h4 { font-size: 13px; font-weight: 600; color: var(--text-muted); margin-bottom: 8px; margin-top: 16px; letter-spacing: 0.03em; }

.docs-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 13px;
    margin-bottom: 8px;
}

.docs-table th {
    text-align: left;
    padding: 8px 12px;
    background: var(--input-bg);
    border-bottom: 1px solid var(--border);
    color: var(--text-secondary);
    font-weight: 600;
}

.docs-table td {
    padding: 8px 12px;
    border-bottom: 1px solid var(--border);
    color: var(--text);
}

.docs-table code {
    font-family: 'SF Mono', 'Fira Code', monospace;
    font-size: 12px;
    background: var(--code-bg);
    padding: 2px 5px;
    border-radius: 3px;
    color: var(--blue);
}

.code-block {
    background: var(--code-bg);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 16px;
    font-family: 'SF Mono', 'Fira Code', monospace;
    font-size: 13px;
    line-height: 1.6;
    color: var(--text);
    overflow-x: auto;
    white-space: pre;
}

.docs-list {
    list-style: disc;
    padding-left: 20px;
    color: var(--text-secondary);
    font-size: 14px;
    line-height: 1.8;
}

.docs-list strong { color: var(--text); }

/* ===== Conversion Table ===== */
.table-actions {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 16px;
}

.table-back-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 13px;
    font-weight: 600;
    color: var(--blue);
    padding: 6px 12px;
    border-radius: var(--radius-sm);
    transition: background 0.15s;
}

.table-back-link:hover { background: var(--blue-light); }

.table-link-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 12.5px;
    font-weight: 600;
    color: var(--blue);
    padding: 6px 12px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    background: var(--card);
    transition: background 0.15s, border-color 0.15s;
}

.table-link-btn:hover {
    background: var(--blue-light);
    border-color: rgba(37, 99, 235, 0.3);
}

.conversion-table-wrapper {
    background: var(--card);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    transition: background 0.3s;
}

.conversion-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 13px;
    font-variant-numeric: tabular-nums;
    white-space: nowrap;
}

.conversion-table th,
.conversion-table td {
    padding: 10px 12px;
    border: 1px solid var(--border);
    text-align: right;
}

.conversion-table thead th {
    background: var(--input-bg);
    color: var(--text-secondary);
    font-weight: 700;
    position: sticky;
    top: 0;
    z-index: 2;
}

.conversion-table-corner {
    position: sticky;
    left: 0;
    z-index: 3 !important;
    background: var(--input-bg) !important;
    text-align: center !important;
    min-width: 70px;
}

.corner-from,
.corner-to {
    display: block;
    font-size: 10px;
    font-weight: 600;
    color: var(--text-muted);
    letter-spacing: 0.05em;
}

.corner-from { text-align: left; }
.corner-to { text-align: right; }

.conversion-table-col-header {
    font-size: 12px;
    min-width: 80px;
    text-align: center !important;
}

.conversion-table-row-header {
    position: sticky;
    left: 0;
    z-index: 1;
    background: var(--input-bg);
    color: var(--text);
    font-weight: 700;
    text-align: left !important;
    font-size: 12px;
    min-width: 70px;
}

.conversion-table-cell {
    color: var(--text);
    font-family: 'SF Mono', 'Fira Code', monospace;
    font-size: 12px;
}

.conversion-table-identity {
    background: var(--blue-light);
    color: var(--blue);
    font-weight: 700;
}

.conversion-table-cell:hover {
    background: rgba(37, 99, 235, 0.06);
}

.table-legend {
    margin-top: 16px;
    padding: 0 4px;
}

.table-legend p {
    font-size: 12.5px;
    color: var(--text-muted);
    line-height: 1.6;
}

/* ===== Responsive ===== */
@media (max-width: 900px) {
    .sidebar {
        transform: translateX(-100%);
        transition: transform 0.3s;
    }
    .sidebar.open { transform: translateX(0); }
    .main-wrapper { margin-left: 0; }
    .mobile-menu-btn { display: flex; }
    .convert-body { flex-direction: column; align-items: stretch; }
    .swap-btn { margin: 0 auto; transform: rotate(90deg); }
    .swap-btn:hover { transform: rotate(90deg) scale(1.05); }
    .category-cards { grid-template-columns: 1fr 1fr; }
    .converter-group-grid { grid-template-columns: 1fr 1fr; }
    .convert-meta { flex-direction: column; gap: 4px; }
    .content { padding: 24px 16px; }
    .category-header { flex-direction: column; align-items: flex-start; gap: 10px; }
    .category-header-actions { margin-left: 0; }
}

@media (max-width: 500px) {
    .category-cards { grid-template-columns: 1fr; }
    .converter-group-grid { grid-template-columns: 1fr; }
}