/* ═══════════════════════════════════════════════════════════════
   unit-tool.css  -  Premium light-theme Unit Converter UI
   Scoped entirely under .uc-wrap to avoid collisions
   ═══════════════════════════════════════════════════════════════ */

/* ── Reset / Scope ──────────────────────────────────────────── */
.uc-wrap *, .uc-wrap *::before, .uc-wrap *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

.uc-wrap {
    --uc-font: 'Inter', system-ui, -apple-system, sans-serif;
    --uc-radius: 12px;
    --uc-radius-sm: 8px;
    --uc-shadow: 0 1px 3px rgba(0,0,0,.08), 0 4px 16px rgba(0,0,0,.06);
    --uc-shadow-lg: 0 4px 24px rgba(0,0,0,.10), 0 1px 4px rgba(0,0,0,.06);
    --uc-border: #e5e7eb;
    --uc-bg: #ffffff;
    --uc-surface: #f9fafb;
    --uc-text: #111827;
    --uc-muted: #6b7280;
    --uc-subtle: #9ca3af;

    /* Category accent palette */
    --uc-length-color:  #2563eb;  --uc-length-light:  #eff6ff;  --uc-length-ring:  #bfdbfe;
    --uc-weight-color:  #7c3aed;  --uc-weight-light:  #f5f3ff;  --uc-weight-ring:  #ddd6fe;
    --uc-temp-color:    #dc2626;  --uc-temp-light:    #fef2f2;  --uc-temp-ring:    #fecaca;
    --uc-speed-color:   #059669;  --uc-speed-light:   #ecfdf5;  --uc-speed-ring:   #a7f3d0;
    --uc-data-color:    #d97706;  --uc-data-light:    #fffbeb;  --uc-data-ring:    #fde68a;

    /* Active accent (JS overrides these via data-cat attribute) */
    --uc-accent:  var(--uc-length-color);
    --uc-accent-light: var(--uc-length-light);
    --uc-accent-ring:  var(--uc-length-ring);

    font-family: var(--uc-font);
    color: var(--uc-text);
    max-width: 780px;
    margin: 0 auto;
    padding: 0 16px 60px;
}

/* Category accents applied via data attribute on .uc-wrap */
.uc-wrap[data-cat="length"]      { --uc-accent: var(--uc-length-color); --uc-accent-light: var(--uc-length-light); --uc-accent-ring: var(--uc-length-ring); }
.uc-wrap[data-cat="weight"]      { --uc-accent: var(--uc-weight-color); --uc-accent-light: var(--uc-weight-light); --uc-accent-ring: var(--uc-weight-ring); }
.uc-wrap[data-cat="temperature"] { --uc-accent: var(--uc-temp-color);   --uc-accent-light: var(--uc-temp-light);   --uc-accent-ring: var(--uc-temp-ring);   }
.uc-wrap[data-cat="speed"]       { --uc-accent: var(--uc-speed-color);  --uc-accent-light: var(--uc-speed-light);  --uc-accent-ring: var(--uc-speed-ring);  }
.uc-wrap[data-cat="data"]        { --uc-accent: var(--uc-data-color);   --uc-accent-light: var(--uc-data-light);   --uc-accent-ring: var(--uc-data-ring);   }


/* ── Hero ───────────────────────────────────────────────────── */
.uc-hero {
    text-align: center;
    padding: 40px 20px 32px;
}
.uc-hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background: var(--uc-accent-light);
    color: var(--uc-accent);
    border: 1px solid var(--uc-accent-ring);
    border-radius: 100px;
    font-size: 12.5px;
    font-weight: 600;
    padding: 5px 14px;
    margin-bottom: 18px;
    transition: background .25s, color .25s, border-color .25s;
}
.uc-hero-badge svg { width: 14px; height: 14px; }
.uc-hero h1 {
    font-size: clamp(26px, 5vw, 38px);
    font-weight: 800;
    letter-spacing: -0.5px;
    line-height: 1.15;
    margin-bottom: 12px;
    color: var(--uc-text);
}
.uc-hero p {
    font-size: 15.5px;
    color: var(--uc-muted);
    max-width: 560px;
    margin: 0 auto;
    line-height: 1.65;
}

/* ── Card ───────────────────────────────────────────────────── */
.uc-card {
    background: var(--uc-bg);
    border: 1px solid var(--uc-border);
    border-radius: var(--uc-radius);
    box-shadow: var(--uc-shadow);
    margin-bottom: 18px;
    overflow: hidden;
    transition: box-shadow .2s;
}
.uc-card:hover { box-shadow: var(--uc-shadow-lg); }

/* ── Category Tabs ──────────────────────────────────────────── */
.uc-tabs {
    display: flex;
    gap: 0;
    background: var(--uc-surface);
    border-bottom: 1px solid var(--uc-border);
    overflow-x: auto;
    scrollbar-width: none;
    -webkit-overflow-scrolling: touch;
}
.uc-tabs::-webkit-scrollbar { display: none; }

.uc-tab {
    display: flex;
    align-items: center;
    gap: 7px;
    padding: 13px 20px;
    border: none;
    background: transparent;
    color: var(--uc-muted);
    font-size: 13.5px;
    font-weight: 600;
    font-family: var(--uc-font);
    cursor: pointer;
    white-space: nowrap;
    border-bottom: 2.5px solid transparent;
    transition: color .18s, border-color .18s, background .18s;
    position: relative;
}
.uc-tab svg { width: 15px; height: 15px; flex-shrink: 0; }
.uc-tab:hover {
    color: var(--uc-accent);
    background: var(--uc-accent-light);
}
.uc-tab.is-active {
    color: var(--uc-accent);
    border-bottom-color: var(--uc-accent);
    background: var(--uc-bg);
}

/* Category dot badge on each tab */
.uc-tab-dot {
    width: 7px;
    height: 7px;
    border-radius: 50%;
    flex-shrink: 0;
}
.uc-tab[data-cat="length"]      .uc-tab-dot { background: var(--uc-length-color); }
.uc-tab[data-cat="weight"]      .uc-tab-dot { background: var(--uc-weight-color); }
.uc-tab[data-cat="temperature"] .uc-tab-dot { background: var(--uc-temp-color); }
.uc-tab[data-cat="speed"]       .uc-tab-dot { background: var(--uc-speed-color); }
.uc-tab[data-cat="data"]        .uc-tab-dot { background: var(--uc-data-color); }

/* ── Converter Body ─────────────────────────────────────────── */
.uc-body {
    padding: 28px 28px 24px;
}

/* ── Converter Grid ─────────────────────────────────────────── */
.uc-converter-grid {
    display: grid;
    grid-template-columns: 1fr auto 1fr;
    align-items: end;
    gap: 14px;
}

.uc-field-label {
    font-size: 11.5px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.6px;
    color: var(--uc-muted);
    margin-bottom: 7px;
}

.uc-input-wrap {
    position: relative;
    display: flex;
    flex-direction: column;
}

.uc-number-input {
    width: 100%;
    padding: 12px 14px;
    font-size: 18px;
    font-weight: 600;
    font-family: var(--uc-font);
    color: var(--uc-text);
    background: var(--uc-surface);
    border: 1.5px solid var(--uc-border);
    border-radius: var(--uc-radius-sm);
    outline: none;
    transition: border-color .18s, box-shadow .18s, background .18s;
    -moz-appearance: textfield;
}
.uc-number-input::-webkit-inner-spin-button,
.uc-number-input::-webkit-outer-spin-button { -webkit-appearance: none; }
.uc-number-input:focus {
    border-color: var(--uc-accent);
    background: #fff;
    box-shadow: 0 0 0 3px var(--uc-accent-ring);
}

.uc-select {
    width: 100%;
    padding: 10px 34px 10px 12px;
    font-size: 13.5px;
    font-weight: 600;
    font-family: var(--uc-font);
    color: var(--uc-text);
    background: var(--uc-surface) url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%236b7280' stroke-width='2.5' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E") no-repeat right 10px center;
    border: 1.5px solid var(--uc-border);
    border-radius: var(--uc-radius-sm);
    outline: none;
    appearance: none;
    -webkit-appearance: none;
    cursor: pointer;
    transition: border-color .18s, box-shadow .18s;
    margin-top: 7px;
}
.uc-select:focus {
    border-color: var(--uc-accent);
    box-shadow: 0 0 0 3px var(--uc-accent-ring);
}

/* ── Swap Button ────────────────────────────────────────────── */
.uc-swap-col {
    display: flex;
    justify-content: center;
    padding-bottom: 3px;
}

.uc-swap-btn {
    width: 42px;
    height: 42px;
    border-radius: 50%;
    border: 1.5px solid var(--uc-border);
    background: var(--uc-bg);
    color: var(--uc-muted);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all .2s;
    flex-shrink: 0;
    box-shadow: 0 1px 4px rgba(0,0,0,.07);
}
.uc-swap-btn svg { width: 17px; height: 17px; }
.uc-swap-btn:hover {
    background: var(--uc-accent);
    border-color: var(--uc-accent);
    color: #fff;
    transform: rotate(180deg);
    box-shadow: 0 4px 12px rgba(0,0,0,.15);
}

/* ── Output Area ────────────────────────────────────────────── */
.uc-output-wrap {
    margin-top: 24px;
    background: var(--uc-accent-light);
    border: 1.5px solid var(--uc-accent-ring);
    border-radius: var(--uc-radius-sm);
    padding: 18px 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    transition: background .25s, border-color .25s;
    min-height: 72px;
}
.uc-output-left { flex: 1; min-width: 0; }
.uc-output-label {
    font-size: 11px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.7px;
    color: var(--uc-accent);
    margin-bottom: 4px;
    opacity: 0.8;
}
.uc-output-value {
    font-size: 26px;
    font-weight: 800;
    color: var(--uc-accent);
    letter-spacing: -0.5px;
    word-break: break-all;
    transition: color .25s;
}
.uc-output-unit {
    font-size: 14px;
    font-weight: 600;
    color: var(--uc-accent);
    opacity: 0.65;
    margin-left: 6px;
}
.uc-output-formula {
    font-size: 11.5px;
    color: var(--uc-muted);
    margin-top: 5px;
    font-style: italic;
}

.uc-copy-btn {
    flex-shrink: 0;
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 8px 14px;
    border-radius: var(--uc-radius-sm);
    border: 1.5px solid var(--uc-accent-ring);
    background: var(--uc-bg);
    color: var(--uc-accent);
    font-size: 12.5px;
    font-weight: 700;
    font-family: var(--uc-font);
    cursor: pointer;
    transition: all .18s;
    white-space: nowrap;
}
.uc-copy-btn svg { width: 14px; height: 14px; }
.uc-copy-btn:hover {
    background: var(--uc-accent);
    color: #fff;
    border-color: var(--uc-accent);
}
.uc-copy-btn.copied {
    background: var(--uc-accent);
    color: #fff;
    border-color: var(--uc-accent);
}

/* ── Quick Reference Table ──────────────────────────────────── */
.uc-ref-wrap {
    margin-top: 20px;
}
.uc-ref-toggle {
    display: flex;
    align-items: center;
    gap: 7px;
    font-size: 12.5px;
    font-weight: 700;
    color: var(--uc-muted);
    background: none;
    border: none;
    cursor: pointer;
    font-family: var(--uc-font);
    padding: 0;
    transition: color .18s;
}
.uc-ref-toggle:hover { color: var(--uc-accent); }
.uc-ref-toggle svg { width: 14px; height: 14px; transition: transform .2s; }
.uc-ref-toggle.open svg { transform: rotate(180deg); }

.uc-ref-table-wrap {
    display: none;
    margin-top: 12px;
    border: 1px solid var(--uc-border);
    border-radius: var(--uc-radius-sm);
    overflow: hidden;
}
.uc-ref-table-wrap.open { display: block; }

.uc-ref-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 13px;
}
.uc-ref-table th {
    background: var(--uc-surface);
    padding: 9px 14px;
    text-align: left;
    font-size: 11px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--uc-muted);
    border-bottom: 1px solid var(--uc-border);
}
.uc-ref-table td {
    padding: 9px 14px;
    border-bottom: 1px solid var(--uc-border);
    color: var(--uc-text);
    font-weight: 500;
}
.uc-ref-table tr:last-child td { border-bottom: none; }
.uc-ref-table tr:nth-child(even) td { background: var(--uc-surface); }
.uc-ref-table td:first-child { font-weight: 700; color: var(--uc-accent); }

/* ── History Panel ──────────────────────────────────────────── */
.uc-history-card .uc-card-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 22px;
    border-bottom: 1px solid var(--uc-border);
}
.uc-card-header-left {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 13.5px;
    font-weight: 700;
    color: var(--uc-text);
}
.uc-card-header-left svg { width: 15px; height: 15px; color: var(--uc-muted); }

.uc-clear-btn {
    font-size: 12px;
    font-weight: 600;
    color: var(--uc-muted);
    background: none;
    border: 1px solid var(--uc-border);
    border-radius: 6px;
    padding: 4px 10px;
    cursor: pointer;
    font-family: var(--uc-font);
    transition: color .18s, border-color .18s;
}
.uc-clear-btn:hover { color: #dc2626; border-color: #fca5a5; }

.uc-history-list {
    padding: 8px 0;
    max-height: 260px;
    overflow-y: auto;
}
.uc-history-empty {
    text-align: center;
    padding: 28px 20px;
    color: var(--uc-subtle);
    font-size: 13.5px;
}
.uc-history-empty svg { width: 32px; height: 32px; opacity: .3; margin-bottom: 8px; display: block; margin-inline: auto; }

.uc-history-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 10px 22px;
    border-bottom: 1px solid var(--uc-border);
    font-size: 13.5px;
    transition: background .15s;
    cursor: default;
}
.uc-history-item:last-child { border-bottom: none; }
.uc-history-item:hover { background: var(--uc-surface); }

.uc-history-expression {
    font-weight: 600;
    color: var(--uc-text);
}
.uc-history-result {
    font-weight: 700;
    color: var(--uc-accent);
    margin-left: 10px;
    flex-shrink: 0;
}
.uc-history-cat-badge {
    font-size: 10.5px;
    font-weight: 700;
    padding: 2px 8px;
    border-radius: 100px;
    flex-shrink: 0;
}

/* cat colours for history badge */
.uc-badge-length      { background:#eff6ff; color:#2563eb; }
.uc-badge-weight      { background:#f5f3ff; color:#7c3aed; }
.uc-badge-temperature { background:#fef2f2; color:#dc2626; }
.uc-badge-speed       { background:#ecfdf5; color:#059669; }
.uc-badge-data        { background:#fffbeb; color:#d97706; }

/* ── SEO Content ────────────────────────────────────────────── */
.uc-seo-section {
    background: var(--uc-bg);
    border: 1px solid var(--uc-border);
    border-radius: var(--uc-radius);
    box-shadow: var(--uc-shadow);
    overflow: hidden;
    margin-bottom: 18px;
}
.uc-seo-header {
    padding: 20px 24px 0;
}
.uc-seo-header h2 {
    font-size: 17px;
    font-weight: 800;
    color: var(--uc-text);
    margin-bottom: 8px;
}
.uc-seo-header p {
    font-size: 13.5px;
    color: var(--uc-muted);
    line-height: 1.65;
    margin-bottom: 16px;
}

/* ── FAQ ────────────────────────────────────────────────────── */
.uc-faq-list { padding: 4px 0 8px; }
.uc-faq-item {
    border-top: 1px solid var(--uc-border);
}
.uc-faq-q {
    width: 100%;
    text-align: left;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 15px 24px;
    font-size: 14px;
    font-weight: 700;
    color: var(--uc-text);
    background: none;
    border: none;
    cursor: pointer;
    font-family: var(--uc-font);
    gap: 12px;
    transition: color .18s;
}
.uc-faq-q svg { width: 16px; height: 16px; flex-shrink: 0; color: var(--uc-muted); transition: transform .22s; }
.uc-faq-q:hover { color: var(--uc-accent); }
.uc-faq-q.open { color: var(--uc-accent); }
.uc-faq-q.open svg { transform: rotate(180deg); }
.uc-faq-a {
    display: none;
    padding: 0 24px 16px;
    font-size: 13.5px;
    color: var(--uc-muted);
    line-height: 1.7;
}
.uc-faq-a.open { display: block; }

/* ── Responsive ─────────────────────────────────────────────── */
@media (max-width: 600px) {
    .uc-body { padding: 18px 16px 16px; }
    .uc-converter-grid {
        grid-template-columns: 1fr;
        grid-template-rows: auto auto auto;
        gap: 10px;
    }
    .uc-swap-col { justify-content: flex-start; }
    .uc-swap-btn { width: 38px; height: 38px; transform: rotate(90deg); }
    .uc-swap-btn:hover { transform: rotate(270deg); }
    .uc-output-value { font-size: 20px; }
    .uc-output-wrap { flex-direction: column; align-items: flex-start; gap: 10px; }
    .uc-copy-btn { align-self: flex-start; }
    .uc-tab { padding: 11px 14px; font-size: 12.5px; }
    .uc-hero { padding: 26px 12px 22px; }
    .uc-history-item { flex-wrap: wrap; gap: 4px; }
}

/* ── Transitions / Animations ───────────────────────────────── */
.uc-output-value.flash {
    animation: uc-flash .25s ease;
}
@keyframes uc-flash {
    0%   { opacity: 0.3; transform: translateY(4px); }
    100% { opacity: 1;   transform: translateY(0); }
}
.uc-history-item.new-entry {
    animation: uc-slide-in .22s ease;
}
@keyframes uc-slide-in {
    from { opacity: 0; transform: translateX(-10px); }
    to   { opacity: 1; transform: translateX(0); }
}

/* scrollbar style for history */
.uc-history-list::-webkit-scrollbar { width: 5px; }
.uc-history-list::-webkit-scrollbar-thumb { background: var(--uc-border); border-radius: 10px; }

/* number input on output side - readonly look */
.uc-output-input {
    background: transparent;
    border: none;
    outline: none;
    font-size: 26px;
    font-weight: 800;
    color: var(--uc-accent);
    width: 100%;
    font-family: var(--uc-font);
    letter-spacing: -0.5px;
    cursor: default;
    caret-color: transparent;
}