/**
 * ChemStage Chemistry Calculator Suite v3.1 — Styles
 *
 * Brand: ChemStage.com
 * Primary: #33a5f7  Accent: #4CAF50  Dark: #1a1a2e
 * Font: 'Almarai', system-ui, sans-serif
 *
 * @package ChemStage_Chemistry_Calculator
 */

/* ==========================================================================
   GOOGLE FONT
   ========================================================================== */
@import url('https://fonts.googleapis.com/css2?family=Almarai:wght@300;400;700;800&display=swap');

/* ==========================================================================
   CSS CUSTOM PROPERTIES (Light & Dark)
   ========================================================================== */
.csuc-app {
    --csuc-primary: #33a5f7;
    --csuc-primary-hover: #1e88e5;
    --csuc-primary-deep: #0d47a1;
    --csuc-primary-light: #e3f2fd;
    --csuc-primary-glow: rgba(51, 165, 247, 0.18);
    --csuc-accent: #4CAF50;
    --csuc-accent-light: #e8f5e9;
    --csuc-danger: #e53935;
    --csuc-warning: #ff9800;
    --csuc-warning-bg: #fff3e0;
    --csuc-warning-border: #ffe0b2;
    --csuc-bg: #f0f4f8;
    --csuc-surface: #ffffff;
    --csuc-surface-hover: #f0f7ff;
    --csuc-surface-alt: #f7f9fc;
    --csuc-border: #e0e6ed;
    --csuc-border-focus: var(--csuc-primary);
    --csuc-text: #1a2332;
    --csuc-text-secondary: #5a6a7e;
    --csuc-text-muted: #8896a6;
    --csuc-shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
    --csuc-shadow-md: 0 4px 12px rgba(0,0,0,0.08);
    --csuc-shadow-lg: 0 8px 30px rgba(0,0,0,0.1);
    --csuc-radius: 12px;
    --csuc-radius-sm: 8px;
    --csuc-radius-xs: 6px;
    --csuc-transition: 0.2s ease;
    --csuc-font: 'Almarai', system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
    --csuc-mono: 'SF Mono', 'Fira Code', 'Consolas', monospace;
    --csuc-result-bg: var(--csuc-accent-light);
    --csuc-result-text: #1b5e20;
    --csuc-result-border: #a5d6a7;
    --csuc-header-from: #1e88e5;
    --csuc-header-to: #42a5f5;
    --csuc-interp-bg: #f3e5f5;
    --csuc-interp-border: #ce93d8;
    --csuc-interp-text: #6a1b9a;
}

/* Dark theme */
.csuc-app.csuc-dark {
    --csuc-bg: #0f1923;
    --csuc-surface: #1a2736;
    --csuc-surface-hover: #1e2f40;
    --csuc-surface-alt: #1e2f40;
    --csuc-border: #2a3d52;
    --csuc-text: #e4eaf1;
    --csuc-text-secondary: #9ab0c6;
    --csuc-text-muted: #6b8299;
    --csuc-shadow-sm: 0 1px 3px rgba(0,0,0,0.2);
    --csuc-shadow-md: 0 4px 12px rgba(0,0,0,0.3);
    --csuc-shadow-lg: 0 8px 30px rgba(0,0,0,0.4);
    --csuc-result-bg: #0d2818;
    --csuc-result-text: #66bb6a;
    --csuc-result-border: #2e7d32;
    --csuc-primary-light: #1a3a5c;
    --csuc-accent-light: #1a3a2a;
    --csuc-warning-bg: #2a1f00;
    --csuc-warning-border: #5a4000;
    --csuc-header-from: #0d47a1;
    --csuc-header-to: #1565c0;
    --csuc-interp-bg: #1a1030;
    --csuc-interp-border: #6a1b9a;
    --csuc-interp-text: #ce93d8;
}

/* ==========================================================================
   RESET & BASE
   ========================================================================== */
.csuc-app *,
.csuc-app *::before,
.csuc-app *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

.csuc-app {
    position: relative;
    font-family: var(--csuc-font);
    font-size: 15px;
    line-height: 1.6;
    color: var(--csuc-text);
    background: var(--csuc-bg);
    border-radius: var(--csuc-radius);
    overflow: hidden;
    max-width: 900px;
    margin: 24px auto;
    box-shadow: var(--csuc-shadow-lg);
    direction: ltr;
    -webkit-font-smoothing: antialiased;
}

.csuc-app.csuc-rtl {
    direction: rtl;
}

/* ==========================================================================
   TOOLBAR (Search + Dark Mode Toggle in one row)
   ========================================================================== */
.csuc-toolbar {
    display: flex;
    align-items: flex-start;
    gap: 12px;
    padding: 16px 20px 0;
    background: var(--csuc-surface);
}

.csuc-toolbar .csuc-search-wrap {
    flex: 1;
    padding: 0;
    background: transparent;
}

.csuc-toolbar-embed {
    justify-content: flex-end;
    padding: 12px 20px 0;
}

/* ==========================================================================
   DARK MODE TOGGLE — Professional pill switch with sun/moon
   ========================================================================== */
.csuc-dm-toggle {
    flex-shrink: 0;
    position: relative;
    background: none;
    border: none;
    padding: 0;
    cursor: pointer;
    margin-top: 4px;
    outline: none;
}

.csuc-dm-track {
    display: flex;
    align-items: center;
    width: 52px;
    height: 28px;
    border-radius: 50px;
    background: var(--csuc-border);
    border: 1.5px solid var(--csuc-border);
    position: relative;
    transition: all 0.3s ease;
    box-shadow: inset 0 1px 3px rgba(0,0,0,0.08);
}

.csuc-dm-thumb {
    position: absolute;
    top: 2px;
    left: 2px;
    width: 22px;
    height: 22px;
    border-radius: 50%;
    background: var(--csuc-surface);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 1px 4px rgba(0,0,0,0.15);
}

.csuc-dm-sun {
    color: #f59e0b;
    display: block;
}

.csuc-dm-moon {
    color: #6366f1;
    display: none;
}

/* Dark mode active state */
.csuc-app.csuc-dark .csuc-dm-track {
    background: #334155;
    border-color: #475569;
}

.csuc-app.csuc-dark .csuc-dm-thumb {
    left: calc(100% - 24px);
    background: #1e293b;
}

.csuc-app.csuc-dark .csuc-dm-sun {
    display: none;
}

.csuc-app.csuc-dark .csuc-dm-moon {
    display: block;
}

/* RTL flip */
.csuc-app.csuc-rtl .csuc-dm-thumb {
    left: auto;
    right: 2px;
}

.csuc-app.csuc-rtl.csuc-dark .csuc-dm-thumb {
    right: calc(100% - 24px);
    left: auto;
}

/* Hover effect */
.csuc-dm-toggle:hover .csuc-dm-track {
    border-color: var(--csuc-primary);
    box-shadow: 0 0 0 3px var(--csuc-primary-glow);
}

.csuc-dm-toggle:focus-visible .csuc-dm-track {
    outline: 2px solid var(--csuc-primary);
    outline-offset: 2px;
}

/* ==========================================================================
   QUICK SEARCH BAR (v3.1)
   ========================================================================== */
.csuc-search-wrap {
    position: relative;
}

.csuc-search-bar {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 0 14px;
    border: 1.5px solid var(--csuc-border);
    border-radius: 50px;
    background: var(--csuc-surface-alt);
    transition: border-color var(--csuc-transition), box-shadow var(--csuc-transition);
}

.csuc-search-bar:focus-within {
    border-color: var(--csuc-primary);
    box-shadow: 0 0 0 3px var(--csuc-primary-glow);
}

.csuc-search-icon {
    flex-shrink: 0;
    color: var(--csuc-text-muted);
}

.csuc-search-input {
    flex: 1;
    border: none;
    background: transparent;
    font-family: var(--csuc-font);
    font-size: 0.88rem;
    color: var(--csuc-text);
    padding: 10px 0;
    outline: none;
}

.csuc-search-input::placeholder {
    color: var(--csuc-text-muted);
    opacity: 0.7;
}

.csuc-search-results {
    position: absolute;
    top: 100%;
    left: 20px;
    right: 20px;
    background: var(--csuc-surface);
    border: 1.5px solid var(--csuc-border);
    border-radius: var(--csuc-radius-sm);
    box-shadow: var(--csuc-shadow-lg);
    z-index: 100;
    max-height: 360px;
    overflow-y: auto;
    margin-top: 4px;
}

.csuc-search-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 16px;
    width: 100%;
    border: none;
    background: transparent;
    cursor: pointer;
    text-align: start;
    font-family: var(--csuc-font);
    transition: background var(--csuc-transition);
    color: var(--csuc-text);
}

.csuc-search-item:hover {
    background: var(--csuc-surface-hover);
}

.csuc-search-item + .csuc-search-item {
    border-top: 1px solid var(--csuc-border);
}

.csuc-search-icon-wrap {
    flex-shrink: 0;
    width: 36px;
    height: 36px;
    background: var(--csuc-primary-light);
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--csuc-primary);
}

.csuc-search-info {
    display: flex;
    flex-direction: column;
    min-width: 0;
}

.csuc-search-title {
    font-weight: 700;
    font-size: 0.88rem;
    color: var(--csuc-text);
}

.csuc-search-cat {
    font-size: 0.72rem;
    color: var(--csuc-text-muted);
}

.csuc-search-empty {
    padding: 16px;
    text-align: center;
    color: var(--csuc-text-muted);
    font-size: 0.85rem;
}

/* ==========================================================================
   NAVIGATION (Category Pills)
   ========================================================================== */
.csuc-nav {
    background: var(--csuc-surface);
    border-bottom: 1px solid var(--csuc-border);
    position: relative;
}

.csuc-nav-scroll {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    padding: 12px 20px;
}

.csuc-pill {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 16px;
    border: 1.5px solid var(--csuc-border);
    border-radius: 50px;
    background: var(--csuc-surface);
    color: var(--csuc-text-secondary);
    font-family: var(--csuc-font);
    font-size: 0.82rem;
    font-weight: 400;
    white-space: nowrap;
    cursor: pointer;
    transition: all var(--csuc-transition);
    line-height: 1.3;
}

.csuc-pill:hover {
    border-color: var(--csuc-primary);
    color: var(--csuc-primary);
    background: var(--csuc-primary-light);
}

.csuc-pill.csuc-active {
    background: var(--csuc-primary);
    color: #fff;
    border-color: var(--csuc-primary);
    font-weight: 700;
    box-shadow: 0 2px 8px var(--csuc-primary-glow);
}

.csuc-pill-icon {
    display: inline-flex;
    align-items: center;
}

.csuc-pill-icon svg {
    width: 16px;
    height: 16px;
}

.csuc-pill.csuc-active .csuc-pill-icon svg {
    stroke: #fff;
}

/* ==========================================================================
   MAIN CONTENT AREA
   ========================================================================== */
.csuc-main {
    padding: 20px;
    min-height: 300px;
}

/* ==========================================================================
   EMPTY STATE (Favorites page when empty)
   ========================================================================== */
.csuc-empty-state {
    text-align: center;
    padding: 3rem 1rem;
    color: var(--csuc-text-muted);
}
.csuc-empty-state svg {
    margin: 0 auto 1rem;
    display: block;
}
.csuc-empty-state p {
    font-size: 1rem;
    line-height: 1.6;
    max-width: 320px;
    margin: 0 auto;
}

/* ==========================================================================
   SECTION LABELS (Favorites, Recent, All Tools)
   ========================================================================== */
.csuc-section-label {
    font-size: 0.82rem;
    font-weight: 700;
    color: var(--csuc-text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin: 18px 0 10px;
    padding-bottom: 6px;
    border-bottom: 1px solid var(--csuc-border);
    display: flex;
    align-items: center;
    gap: 6px;
}

.csuc-section-label:first-child {
    margin-top: 0;
}

.csuc-section-label svg {
    flex-shrink: 0;
}

/* ==========================================================================
   TOOL GRID
   ========================================================================== */
.csuc-tool-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 14px;
    margin-bottom: 16px;
}

.csuc-tool-grid-sm {
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 10px;
}

.csuc-tool-card {
    display: flex;
    flex-direction: column;
    gap: 10px;
    padding: 16px;
    background: var(--csuc-surface);
    border: 1.5px solid var(--csuc-border);
    border-radius: var(--csuc-radius);
    cursor: pointer;
    transition: all var(--csuc-transition);
    text-align: start;
    font-family: var(--csuc-font);
    width: 100%;
    position: relative;
}

.csuc-tool-card:hover {
    border-color: var(--csuc-primary);
    box-shadow: var(--csuc-shadow-md);
    transform: translateY(-2px);
    background: var(--csuc-surface-hover);
}

.csuc-tool-card-top {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
}

.csuc-tool-icon {
    flex-shrink: 0;
    width: 44px;
    height: 44px;
    background: var(--csuc-primary-light);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--csuc-primary);
}

.csuc-tool-icon svg {
    width: 22px;
    height: 22px;
    stroke: var(--csuc-primary);
}

.csuc-tool-info {
    min-width: 0;
}

.csuc-tool-title {
    font-weight: 700;
    font-size: 0.95rem;
    color: var(--csuc-text);
    margin-bottom: 3px;
}

.csuc-tool-desc {
    font-size: 0.78rem;
    color: var(--csuc-text-muted);
    line-height: 1.45;
}

/* Favorite button on cards */
.csuc-fav-btn {
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
    color: var(--csuc-text-muted);
    transition: color var(--csuc-transition), transform var(--csuc-transition);
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
}

.csuc-fav-btn:hover {
    color: var(--csuc-warning);
    transform: scale(1.15);
}

.csuc-fav-btn.csuc-fav-active {
    color: var(--csuc-warning);
}

.csuc-fav-btn svg {
    width: 18px;
    height: 18px;
}

/* ==========================================================================
   CALCULATOR VIEW
   ========================================================================== */
.csuc-calc-view {
    animation: csucFadeIn 0.25s ease;
}

.csuc-embed-view .csuc-calc-body {
    max-width: 100%;
}

@keyframes csucFadeIn {
    from { opacity: 0; transform: translateY(8px); }
    to   { opacity: 1; transform: translateY(0); }
}

.csuc-back-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 14px;
    border: 1.5px solid var(--csuc-border);
    border-radius: 50px;
    background: var(--csuc-surface);
    color: var(--csuc-text-secondary);
    font-family: var(--csuc-font);
    font-size: 0.82rem;
    cursor: pointer;
    transition: all var(--csuc-transition);
    margin-bottom: 16px;
}

.csuc-back-btn:hover {
    border-color: var(--csuc-primary);
    color: var(--csuc-primary);
}

.csuc-calc-header {
    display: flex;
    align-items: center;
    gap: 14px;
    margin-bottom: 20px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--csuc-border);
}

.csuc-calc-icon {
    flex-shrink: 0;
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--csuc-primary), var(--csuc-primary-hover));
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
}

.csuc-calc-icon svg {
    width: 24px;
    height: 24px;
    stroke: #fff;
}

.csuc-calc-title {
    font-size: 1.15rem;
    font-weight: 700;
    margin: 0 0 2px;
    color: var(--csuc-text);
}

.csuc-calc-desc {
    font-size: 0.82rem;
    color: var(--csuc-text-muted);
    margin: 0;
}

.csuc-calc-body {
    display: flex;
    flex-direction: column;
    gap: 14px;
    max-width: 640px;
}

/* ==========================================================================
   FORMULA REFERENCE BAR
   ========================================================================== */
.csuc-formula-ref {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 10px 14px;
    background: var(--csuc-primary-light);
    border: 1px solid var(--csuc-border);
    border-left: 3px solid var(--csuc-primary);
    border-radius: var(--csuc-radius-xs);
    font-size: 0.85rem;
}

.csuc-rtl .csuc-formula-ref {
    border-left: 1px solid var(--csuc-border);
    border-right: 3px solid var(--csuc-primary);
}

.csuc-formula-ref-label {
    font-weight: 700;
    color: var(--csuc-primary);
    white-space: nowrap;
}

.csuc-formula-ref-text {
    color: var(--csuc-text);
    font-family: var(--csuc-mono), var(--csuc-font);
    word-break: break-all;
}

/* ==========================================================================
   FORM FIELDS
   ========================================================================== */
.csuc-field {
    display: flex;
    flex-direction: column;
    gap: 5px;
}

.csuc-field label {
    font-size: 0.82rem;
    font-weight: 700;
    color: var(--csuc-text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

.csuc-field-wrap {
    position: relative;
    display: flex;
    align-items: center;
}

.csuc-field-unit {
    position: absolute;
    right: 12px;
    font-size: 0.8rem;
    color: var(--csuc-text-muted);
    pointer-events: none;
    font-weight: 400;
}

.csuc-rtl .csuc-field-unit {
    right: auto;
    left: 12px;
}

.csuc-field input,
.csuc-field select,
.csuc-select {
    width: 100%;
    padding: 11px 14px;
    border: 1.5px solid var(--csuc-border);
    border-radius: var(--csuc-radius-sm);
    background: var(--csuc-surface);
    color: var(--csuc-text);
    font-family: var(--csuc-font);
    font-size: 0.95rem;
    transition: border-color var(--csuc-transition), box-shadow var(--csuc-transition);
    outline: none;
    -webkit-appearance: none;
    appearance: none;
}

.csuc-field input[type="number"],
.csuc-field input[type="text"] {
    font-family: var(--csuc-mono), var(--csuc-font);
}

.csuc-field-wrap .csuc-field-unit ~ input {
    padding-right: 60px;
}

.csuc-rtl .csuc-field-wrap .csuc-field-unit ~ input {
    padding-right: 14px;
    padding-left: 60px;
}

.csuc-field input:focus,
.csuc-field select:focus,
.csuc-select:focus {
    border-color: var(--csuc-primary);
    box-shadow: 0 0 0 3px var(--csuc-primary-glow);
}

.csuc-field input::placeholder {
    color: var(--csuc-text-muted);
    opacity: 0.7;
}

/* Select arrow */
.csuc-select {
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%235a6a7e' stroke-width='2'%3E%3Cpolyline points='6 9 12 15 18 9'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 12px center;
    padding-right: 36px;
    cursor: pointer;
}

.csuc-rtl .csuc-select {
    background-position: left 12px center;
    padding-right: 14px;
    padding-left: 36px;
}

/* Inline fields (for Hess, Raoult, Empirical, etc.) */
.csuc-field-inline {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
    margin-bottom: 8px;
}

.csuc-field-inline label {
    min-width: 90px;
    margin-bottom: 0;
    flex-shrink: 0;
}

.csuc-field-inline .csuc-field-wrap {
    flex: 1;
    min-width: 100px;
}

.csuc-field-inline .csuc-field-unit {
    position: static;
    pointer-events: auto;
    flex-shrink: 0;
}

.csuc-input-sm {
    width: 70px !important;
    padding: 8px 10px !important;
    border: 1.5px solid var(--csuc-border);
    border-radius: var(--csuc-radius-xs);
    font-family: var(--csuc-mono), var(--csuc-font);
    font-size: 0.88rem;
    color: var(--csuc-text);
    background: var(--csuc-surface);
    outline: none;
    transition: border-color var(--csuc-transition), box-shadow var(--csuc-transition);
}

.csuc-input-md {
    width: 140px !important;
    padding: 8px 10px !important;
    border: 1.5px solid var(--csuc-border);
    border-radius: var(--csuc-radius-xs);
    font-family: var(--csuc-mono), var(--csuc-font);
    font-size: 0.88rem;
    color: var(--csuc-text);
    background: var(--csuc-surface);
    outline: none;
    transition: border-color var(--csuc-transition), box-shadow var(--csuc-transition);
}

.csuc-input-sm:focus,
.csuc-input-md:focus {
    border-color: var(--csuc-primary);
    box-shadow: 0 0 0 3px var(--csuc-primary-glow);
}

/* ==========================================================================
   BUTTONS
   ========================================================================== */
.csuc-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 24px;
    border: none;
    border-radius: var(--csuc-radius-sm);
    font-family: var(--csuc-font);
    font-size: 0.92rem;
    font-weight: 700;
    cursor: pointer;
    transition: all var(--csuc-transition);
    line-height: 1.3;
}

.csuc-btn svg {
    width: 18px;
    height: 18px;
}

.csuc-btn-primary {
    background: linear-gradient(135deg, var(--csuc-primary), var(--csuc-primary-hover));
    color: #fff;
    box-shadow: 0 2px 8px var(--csuc-primary-glow);
}

.csuc-btn-primary:hover {
    background: linear-gradient(135deg, var(--csuc-primary-hover), var(--csuc-primary-deep));
    box-shadow: 0 4px 16px var(--csuc-primary-glow);
    transform: translateY(-1px);
}

.csuc-btn-outline {
    background: var(--csuc-surface);
    color: var(--csuc-text-secondary);
    border: 1.5px solid var(--csuc-border);
}

.csuc-btn-outline:hover {
    border-color: var(--csuc-primary);
    color: var(--csuc-primary);
}

.csuc-btn-full {
    width: 100%;
}

.csuc-btn-icon {
    background: var(--csuc-surface);
    border: 1.5px solid var(--csuc-border);
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--csuc-primary);
    transition: all var(--csuc-transition);
    padding: 0;
}

.csuc-btn-icon:hover {
    background: var(--csuc-primary-light);
    border-color: var(--csuc-primary);
}

.csuc-btn-row {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    align-items: center;
}

/* Example button */
.csuc-btn-example {
    background: var(--csuc-accent-light);
    color: var(--csuc-accent);
    border: 1.5px solid var(--csuc-accent);
    font-size: 0.8rem;
    padding: 6px 14px;
    border-radius: 50px;
}

.csuc-btn-example:hover {
    background: var(--csuc-accent);
    color: #fff;
}

.csuc-btn-example svg {
    width: 14px;
    height: 14px;
    stroke: currentColor;
    flex-shrink: 0;
}

/* Reset button (v3.1) */
.csuc-btn-reset {
    background: var(--csuc-surface);
    color: var(--csuc-text-muted);
    border: 1.5px solid var(--csuc-border);
    font-size: 0.8rem;
    padding: 6px 14px;
    border-radius: 50px;
}

.csuc-btn-reset:hover {
    border-color: var(--csuc-danger);
    color: var(--csuc-danger);
}

.csuc-btn-reset svg {
    width: 14px;
    height: 14px;
    stroke: currentColor;
    flex-shrink: 0;
}

/* Copy button (v3.1) */
.csuc-btn-copy {
    background: var(--csuc-surface);
    color: var(--csuc-text-muted);
    border: 1.5px solid var(--csuc-border);
    font-size: 0.8rem;
    padding: 6px 14px;
    border-radius: 50px;
}

.csuc-btn-copy:hover {
    border-color: var(--csuc-primary);
    color: var(--csuc-primary);
}

.csuc-btn-copy svg {
    width: 14px;
    height: 14px;
    stroke: currentColor;
    flex-shrink: 0;
}

/* ==========================================================================
   RESULT BOX
   ========================================================================== */
.csuc-result-box {
    padding: 14px 18px;
    background: var(--csuc-surface);
    border: 1.5px solid var(--csuc-border);
    border-radius: var(--csuc-radius-sm);
    transition: all var(--csuc-transition);
}

.csuc-result-box.csuc-has-result {
    border-color: var(--csuc-result-border);
    background: var(--csuc-result-bg);
}

.csuc-result-label {
    font-size: 0.72rem;
    font-weight: 700;
    color: var(--csuc-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    margin-bottom: 4px;
}

.csuc-result-val {
    font-size: 1.3rem;
    font-weight: 700;
    color: var(--csuc-text);
    word-break: break-all;
    font-family: var(--csuc-mono), var(--csuc-font);
    direction: ltr;
    unicode-bidi: isolate;
    text-align: right;
}

.csuc-app:not(.csuc-rtl) .csuc-result-val {
    text-align: left;
}

.csuc-result-box.csuc-has-result .csuc-result-val {
    color: var(--csuc-result-text);
}

.csuc-result-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 10px;
}

/* ==========================================================================
   INTERPRETATION BOX (v3.1)
   ========================================================================== */
.csuc-interp-box {
    padding: 10px 14px;
    background: var(--csuc-interp-bg);
    border: 1px solid var(--csuc-interp-border);
    border-radius: var(--csuc-radius-xs);
    font-size: 0.84rem;
    color: var(--csuc-interp-text);
    line-height: 1.5;
    font-weight: 600;
    direction: ltr;
    unicode-bidi: isolate;
    text-align: right;
}

.csuc-app:not(.csuc-rtl) .csuc-interp-box {
    text-align: left;
}

/* ==========================================================================
   SMART WARNINGS
   ========================================================================== */
.csuc-warnings {
    margin: 8px 0;
}

.csuc-warning-item {
    display: flex;
    align-items: flex-start;
    gap: 8px;
    padding: 10px 14px;
    background: var(--csuc-warning-bg);
    border: 1px solid var(--csuc-warning-border);
    border-radius: var(--csuc-radius-xs);
    margin-bottom: 6px;
    font-size: 0.82rem;
    color: var(--csuc-warning);
    line-height: 1.5;
}

.csuc-warning-item svg {
    flex-shrink: 0;
    margin-top: 1px;
    stroke: var(--csuc-warning);
}

/* ==========================================================================
   INFO BOX
   ========================================================================== */
.csuc-info-box {
    padding: 10px 14px;
    background: var(--csuc-primary-light);
    border: 1px solid var(--csuc-border);
    border-radius: var(--csuc-radius-xs);
    font-size: 0.82rem;
    color: var(--csuc-text-secondary);
    line-height: 1.5;
}

/* ==========================================================================
   TABLES (Breakdown, Serial Dilution, Oxidation)
   ========================================================================== */
.csuc-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.85rem;
    background: var(--csuc-surface);
    border: 1px solid var(--csuc-border);
    border-radius: var(--csuc-radius-xs);
    overflow: hidden;
}

.csuc-table th {
    background: var(--csuc-surface-alt);
    color: var(--csuc-primary);
    font-weight: 700;
    padding: 10px 12px;
    text-align: inherit;
    border-bottom: 2px solid var(--csuc-border);
    font-size: 0.78rem;
    text-transform: uppercase;
    letter-spacing: 0.03em;
}

.csuc-table td {
    padding: 8px 12px;
    border-bottom: 1px solid var(--csuc-border);
    color: var(--csuc-text);
    font-family: var(--csuc-mono), var(--csuc-font);
    direction: ltr;
    unicode-bidi: isolate;
}

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

.csuc-table tr:hover td {
    background: var(--csuc-surface-hover);
}

/* ==========================================================================
   UNIT CONVERTER SPECIFIC
   ========================================================================== */
.csuc-uc-cats {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    margin-bottom: 18px;
}

.csuc-uc-cat {
    padding: 6px 14px;
    border-radius: 16px;
    border: 1.5px solid var(--csuc-border);
    background: var(--csuc-surface);
    color: var(--csuc-text-secondary);
    font-family: var(--csuc-font);
    font-size: 0.78rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--csuc-transition);
    white-space: nowrap;
}

.csuc-uc-cat:hover {
    border-color: var(--csuc-primary);
    color: var(--csuc-primary);
}

.csuc-uc-cat.csuc-active {
    background: var(--csuc-primary);
    color: #fff;
    border-color: var(--csuc-primary);
}

.csuc-uc-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 14px;
    align-items: end;
}

.csuc-uc-swap-row {
    display: flex;
    justify-content: center;
    margin: 8px 0;
}

.csuc-uc-aux {
    padding: 14px;
    background: var(--csuc-primary-light);
    border: 1px dashed var(--csuc-border);
    border-radius: var(--csuc-radius-xs);
}

/* Footer removed — plugin is embedded within the host site */

/* ==========================================================================
   RESPONSIVE — Tablet
   ========================================================================== */
@media (max-width: 768px) {
    .csuc-app {
        margin: 12px 8px;
        border-radius: var(--csuc-radius-sm);
    }



    .csuc-main {
        padding: 14px;
    }

    .csuc-tool-grid {
        grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
        gap: 10px;
    }

    .csuc-uc-row {
        grid-template-columns: 1fr;
    }

    .csuc-result-grid {
        grid-template-columns: 1fr 1fr;
    }

    .csuc-calc-body {
        max-width: 100%;
    }

    .csuc-search-results {
        left: 10px;
        right: 10px;
    }
}

/* ==========================================================================
   RESPONSIVE — Mobile
   ========================================================================== */
@media (max-width: 480px) {
    .csuc-app {
        margin: 8px 4px;
        border-radius: var(--csuc-radius-xs);
    }

    .csuc-nav-scroll {
        padding: 8px 10px;
        gap: 5px;
    }

    .csuc-pill {
        padding: 6px 12px;
        font-size: 0.75rem;
    }

    .csuc-main {
        padding: 10px;
    }

    .csuc-tool-grid,
    .csuc-tool-grid-sm {
        grid-template-columns: 1fr;
        gap: 8px;
    }

    .csuc-tool-card {
        padding: 12px;
    }

    .csuc-tool-icon {
        width: 38px;
        height: 38px;
    }

    .csuc-calc-header .csuc-calc-icon {
        width: 42px;
        height: 42px;
    }

    .csuc-calc-title {
        font-size: 1.05rem;
    }

    .csuc-result-grid {
        grid-template-columns: 1fr;
    }

    .csuc-result-val {
        font-size: 1.1rem;
    }

    .csuc-uc-cats {
        gap: 4px;
    }

    .csuc-uc-cat {
        padding: 5px 10px;
        font-size: 0.72rem;
    }

    .csuc-field-inline {
        flex-direction: column;
        align-items: stretch;
    }

    .csuc-field-inline label {
        min-width: auto;
    }

    .csuc-input-sm,
    .csuc-input-md {
        width: 100% !important;
    }

    .csuc-btn-row {
        flex-direction: column;
    }

    .csuc-btn-row .csuc-btn {
        width: 100%;
    }


    .csuc-toolbar {
        padding: 10px 10px 0;
        gap: 8px;
    }

    .csuc-search-results {
        left: 6px;
        right: 6px;
    }

    .csuc-dm-track {
        width: 46px;
        height: 24px;
    }

    .csuc-dm-thumb {
        width: 18px;
        height: 18px;
    }

    .csuc-app.csuc-dark .csuc-dm-thumb {
        left: calc(100% - 20px);
    }

    .csuc-app.csuc-rtl .csuc-dm-thumb {
        right: 2px;
        left: auto;
    }

    .csuc-app.csuc-rtl.csuc-dark .csuc-dm-thumb {
        right: calc(100% - 20px);
    }

    .csuc-dm-sun svg,
    .csuc-dm-moon svg {
        width: 12px;
        height: 12px;
    }
}

/* ==========================================================================
   ACCESSIBILITY
   ========================================================================== */
.csuc-pill:focus-visible,
.csuc-tool-card:focus-visible,
.csuc-btn:focus-visible,
.csuc-back-btn:focus-visible,
.csuc-fav-btn:focus-visible,
.csuc-uc-cat:focus-visible,
.csuc-input-sm:focus-visible,
.csuc-input-md:focus-visible,
.csuc-search-input:focus-visible,
.csuc-search-item:focus-visible {
    outline: 2px solid var(--csuc-primary);
    outline-offset: 2px;
}

/* ==========================================================================
   PRINT
   ========================================================================== */
@media print {
    .csuc-app {
        box-shadow: none;
        border: 1px solid #ddd;
    }

    .csuc-dm-toggle,
    .csuc-back-btn,
    .csuc-btn,
    .csuc-fav-btn,
    .csuc-btn-example,
    .csuc-btn-reset,
    .csuc-btn-copy,
    .csuc-search-wrap {
        display: none !important;
    }

    .csuc-result-box.csuc-has-result {
        border: 2px solid #333;
    }
}