/**
 * ============================================================
 * Calc84 Geometry Calculator Styles v10.6.4
 * ============================================================
 * Complete CSS for geometry.html with all SEO and UI components
 * ============================================================
 */

/* ==========================================
   CSS VARIABLES & THEME
   ========================================== */
:root {
    --primary-color: #001a2c;
    --accent-color: #00d4ff;
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --bg-glass: rgba(255,255,255,0.95);
    --shadow: 0 4px 15px rgba(0,0,0,0.08);
    --shadow-lg: 0 10px 40px rgba(0,0,0,0.12);
    --radius: 14px;
    --radius-sm: 8px;
    --border-color: #e2e8f0;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --panel-bg: #ffffff;
    --grid-color: #e5e7eb;
    --header-height: 80px;
}

[data-theme="dark"] {
    --primary-color: #0f172a;
    --bg-primary: #1e293b;
    --bg-secondary: #0f172a;
    --bg-glass: rgba(15,23,42,0.95);
    --shadow: 0 4px 15px rgba(0,0,0,0.3);
    --shadow-lg: 0 10px 40px rgba(0,0,0,0.4);
    --border-color: #334155;
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --panel-bg: #1e293b;
    --grid-color: #334155;
}

/* ==========================================
   GEOMETRY WORKSPACE
   ========================================== */

/* Container establishes height in document flow */
.geometry-container {
    position: relative;
    min-height: calc(100vh - var(--header-height));
    width: 100%;
    display: flex;
    flex-direction: column;
}

/* The actual workspace uses sticky positioning for better scroll behavior */
.geometry-workspace {
    position: sticky;
    top: var(--header-height);
    left: 0;
    right: 0;
    height: calc(100vh - var(--header-height));
    min-height: 500px;
    background: var(--bg-secondary);
    overflow: hidden;
}

.workspace {
    position: absolute;
    inset: 0;
    display: flex;
    flex-direction: column;
    padding-bottom: env(safe-area-inset-bottom, 0);
}

#geoCanvas {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    width: 100%;
    height: 100%;
    background: var(--panel-bg);
    cursor: crosshair;
    touch-action: none;
    z-index: 1;
    /* Performance optimizations */
    image-rendering: optimizeSpeed;
    image-rendering: -moz-crisp-edges;
    image-rendering: -webkit-optimize-contrast;
}

/* ==========================================
   CANVAS BACKGROUND PATTERN
   ========================================== */
.canvas-grid {
    position: absolute;
    inset: 0;
    background-image: 
        linear-gradient(to right, var(--grid-color) 1px, transparent 1px),
        linear-gradient(to bottom, var(--grid-color) 1px, transparent 1px);
    background-size: 20px 20px;
    pointer-events: none;
    z-index: 0;
}

/* ==========================================
   INTERNAL TOOLBAR OVERLAY
   ========================================== */
/* Toolbar allows clicks to pass through to canvas */
.geo-toolbar-overlay {
    position: absolute;
    top: 10px;
    left: 10px;
    right: 10px;
    display: flex;
    justify-content: center;
    gap: 10px;
    padding: 10px;
    background: transparent;
    z-index: 40;
    flex-wrap: wrap;
    pointer-events: none; /* Clicks pass through empty areas */
}

.geo-toolbar-overlay .action-btn {
    pointer-events: auto; /* But buttons are clickable */
}

@media (max-width: 768px) {
    .geo-toolbar-overlay {
        gap: 6px;
        padding: 8px;
        left: 5px;
        right: 5px;
    }
    
    .geo-toolbar-overlay .action-btn {
        padding: 8px 12px;
        font-size: 12px;
        min-height: 40px;
    }
    
    .geo-toolbar-overlay .action-btn .hide-mobile {
        display: none;
    }
}

.action-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 16px;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-weight: 500;
    color: var(--text-primary);
    cursor: pointer;
    transition: all 0.2s ease;
}

.action-btn:hover {
    background: var(--accent-color);
    color: white;
    transform: translateY(-1px);
}

.action-btn.danger {
    border-color: #ef4444;
    color: #ef4444;
}

.action-btn.danger:hover {
    background: #ef4444;
    color: white;
}

.action-btn svg {
    width: 16px;
    height: 16px;
}

/* ==========================================
   ZOOM CONTROLS
   ========================================== */
.zoom-controls {
    position: absolute;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 8px;
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    padding: 8px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
    z-index: 60;
    transition: transform 0.3s ease, bottom 0.3s ease;
    pointer-events: auto;
    will-change: transform;
}

@media (max-width: 768px) {
    .zoom-controls {
        bottom: 10px;
        padding: 6px;
        gap: 6px;
    }
    
    .zoom-btn {
        width: 44px;
        height: 44px;
    }
}

.zoom-btn {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    font-size: 20px;
    font-weight: bold;
    color: var(--text-primary);
    cursor: pointer;
    transition: all 0.2s ease;
    pointer-events: auto;
    user-select: none;
    -webkit-user-select: none;
}

.zoom-btn:hover {
    background: var(--accent-color);
    color: white;
    border-color: var(--accent-color);
    transform: scale(1.1);
}

.zoom-btn:active {
    transform: scale(0.95);
}

/* ==========================================
   INFO PANEL
   ========================================== */
.info-panel {
    position: absolute;
    top: 70px;
    right: 20px;
    width: 280px;
    max-height: calc(100vh - 200px);
    background: var(--panel-bg);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
    padding: 15px;
    z-index: 45;
    display: none;
    overflow-y: auto;
    transition: opacity 0.2s ease;
    pointer-events: auto; /* Capture events when visible */
}

@media (max-width: 768px) {
    .info-panel {
        width: calc(100% - 40px);
        max-width: 300px;
        left: 50%;
        right: auto;
        transform: translateX(-50%);
        top: 120px;
        max-height: calc(100vh - 250px);
    }
}

.info-panel.active {
    display: block;
    animation: panelFadeIn 0.2s ease;
}

@keyframes panelFadeIn {
    from {
        opacity: 0;
        transform: translateX(-50%) scale(0.95);
    }
    to {
        opacity: 1;
        transform: translateX(-50%) scale(1);
    }
}

@media (min-width: 769px) {
    .info-panel.active {
        animation: panelFadeInDesktop 0.2s ease;
    }
    
    @keyframes panelFadeInDesktop {
        from {
            opacity: 0;
            transform: scale(0.95);
        }
        to {
            opacity: 1;
            transform: scale(1);
        }
    }
}

.info-panel .panel-header {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 12px;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--border-color);
}

.properties-placeholder {
    text-align: center;
    color: var(--text-secondary);
    padding: 20px;
    font-style: italic;
    font-size: 14px;
}

.property-item {
    display: flex;
    justify-content: space-between;
    padding: 8px 0;
    border-bottom: 1px solid var(--border-color);
}

.property-item:last-child {
    border-bottom: none;
}

.property-label {
    color: var(--text-secondary);
    font-size: 13px;
}

.property-value {
    color: var(--text-primary);
    font-weight: 500;
    font-family: 'Fira Code', monospace;
    font-size: 13px;
}

/* ==========================================
   CONTROLS OVERLAY (BOTTOM PANEL)
   ========================================== */
.controls-overlay {
    position: absolute;
    bottom: 100px;
    left: 20px;
    right: 20px;
    background: var(--bg-glass);
    backdrop-filter: blur(15px);
    -webkit-backdrop-filter: blur(15px);
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-color);
    z-index: 50;
    max-height: 45vh;
    overflow-y: auto;
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1), opacity 0.3s ease;
    will-change: transform, opacity;
    pointer-events: auto; /* Capture events on the panel */
}

/* Canvas container fills the workspace */
#canvasContainer {
    position: relative;
    width: 100%;
    height: 100%;
}

.controls-overlay.collapsed {
    transform: translateY(calc(100% + 10px));
    opacity: 0;
    pointer-events: none;
}

.controls-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 20px;
    cursor: pointer;
    border-bottom: 1px solid var(--border-color);
    font-weight: 600;
    font-size: 14px;
    color: var(--text-primary);
    user-select: none;
    position: relative;
}

.controls-header:hover {
    background: var(--bg-secondary);
}

.controls-content {
    padding: 15px 20px;
}

.controls-content.minimized {
    display: none;
}

/* ==========================================
   MODE TABS
   ========================================== */
.mode-tabs {
    display: flex;
    gap: 8px;
    margin-bottom: 15px;
    padding-bottom: 10px;
    border-bottom: 1px solid var(--border-color);
}

.tab-btn {
    flex: 1;
    padding: 10px 16px;
    background: var(--bg-secondary);
    border: 2px solid transparent;
    border-radius: 10px;
    font-size: 14px;
    font-weight: 600;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.2s ease;
}

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

.tab-btn.active {
    background: var(--accent-color);
    color: white;
    border-color: var(--accent-color);
}

/* ==========================================
   CONTROL GROUPS
   ========================================== */
.control-group {
    margin-bottom: 15px;
}

.control-group-title {
    font-size: 12px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-secondary);
    margin-bottom: 10px;
}

.control-group-header {
    margin-bottom: 12px;
}

/* ==========================================
   FUNCTION INPUT
   ========================================== */
.func-input-group {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 10px;
}

.func-label {
    font-family: 'Fira Code', monospace;
    font-size: 14px;
    font-weight: 600;
    color: var(--accent-color);
    min-width: 30px;
}

.func-label.small {
    min-width: 25px;
    font-size: 12px;
}

.func-input {
    flex: 1;
    padding: 10px 14px;
    background: var(--bg-primary);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    font-family: 'Fira Code', monospace;
    font-size: 14px;
    color: var(--text-primary);
    outline: none;
    transition: border-color 0.2s ease;
}

.func-input:focus {
    border-color: var(--accent-color);
}

/* ==========================================
   SLIDERS
   ========================================== */
.slider-group {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 12px;
}

.slider-group span:first-child {
    font-size: 13px;
    color: var(--text-secondary);
    min-width: 50px;
}

.slider {
    flex: 1;
    height: 6px;
    background: var(--bg-secondary);
    border-radius: 3px;
    outline: none;
    -webkit-appearance: none;
    appearance: none;
}

.slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 18px;
    height: 18px;
    background: var(--accent-color);
    border-radius: 50%;
    cursor: pointer;
    transition: transform 0.15s ease;
}

.slider::-webkit-slider-thumb:hover {
    transform: scale(1.1);
}

.slider::-moz-range-thumb {
    width: 18px;
    height: 18px;
    background: var(--accent-color);
    border-radius: 50%;
    cursor: pointer;
    border: none;
}

/* ==========================================
   SLICER SECTION
   ========================================== */
.slicer-section {
    background: var(--bg-secondary);
    border-radius: 10px;
    padding: 12px;
    margin-top: 10px;
}

.slicer-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px;
}

.slicer-header span {
    font-weight: 600;
    font-size: 14px;
    color: var(--text-primary);
}

.slicer-inputs {
    display: flex;
    gap: 10px;
    margin-bottom: 10px;
}

.slicer-inputs select,
.slicer-inputs input {
    padding: 8px 12px;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 13px;
    color: var(--text-primary);
}

.slicer-inputs select {
    flex: 0 0 100px;
}

.slicer-inputs input {
    flex: 1;
}

/* ==========================================
   TOGGLE SWITCH
   ========================================== */
.stat-toggle {
    position: relative;
    display: inline-block;
    width: 44px;
    height: 24px;
}

.stat-toggle input {
    opacity: 0;
    width: 0;
    height: 0;
}

.stat-toggle-slider {
    position: absolute;
    cursor: pointer;
    inset: 0;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 24px;
    transition: 0.3s;
}

.stat-toggle-slider::before {
    position: absolute;
    content: "";
    height: 18px;
    width: 18px;
    left: 2px;
    bottom: 2px;
    background: var(--text-secondary);
    border-radius: 50%;
    transition: 0.3s;
}

.stat-toggle input:checked + .stat-toggle-slider {
    background: var(--accent-color);
    border-color: var(--accent-color);
}

.stat-toggle input:checked + .stat-toggle-slider::before {
    transform: translateX(20px);
    background: white;
}

/* ==========================================
   GEO TOOLBAR
   ========================================== */
.geo-toolbar {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 15px;
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
    scrollbar-width: none;
}

.geo-toolbar::-webkit-scrollbar {
    display: none;
}

@media (max-width: 768px) {
    .geo-toolbar {
        flex-wrap: nowrap;
        padding-bottom: 8px;
    }
}

.geo-toolbar.compact {
    margin-bottom: 0;
}

.tool-btn {
    display: inline-flex;
    flex-direction: column;
    align-items: center;
    gap: 4px;
    padding: 12px 14px;
    background: var(--bg-primary);
    border: 2px solid var(--border-color);
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.2s ease;
    min-width: 64px;
    min-height: 64px;
    touch-action: manipulation;
    -webkit-tap-highlight-color: rgba(0,0,0,0.1);
}

@media (max-width: 768px) {
    .tool-btn {
        min-width: 56px;
        min-height: 56px;
        padding: 10px 12px;
    }
    
    .tool-btn span:first-child {
        font-size: 20px;
    }
    
    .tool-btn span:last-child {
        font-size: 10px;
    }
}

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

.tool-btn:active {
    transform: translateY(0) scale(0.95);
    background: var(--accent-color);
    color: white;
}

.tool-btn.active {
    background: var(--accent-color);
    border-color: var(--accent-color);
    color: white;
}

.tool-btn span:first-child {
    font-size: 18px;
}

.tool-btn span:last-child {
    font-size: 11px;
    font-weight: 500;
}

.tool-btn .shortcut {
    font-size: 10px;
    color: var(--text-secondary);
    background: var(--bg-secondary);
    padding: 2px 5px;
    border-radius: 4px;
}

.tool-btn.active .shortcut {
    background: rgba(255,255,255,0.2);
    color: rgba(255,255,255,0.9);
}

/* ==========================================
   CHECKBOX LABEL
   ========================================== */
.checkbox-label {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    font-size: 13px;
    color: var(--text-secondary);
}

.checkbox-label input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
    accent-color: var(--accent-color);
}

/* ==========================================
   DISPLAY SETTINGS
   ========================================== */
.display-settings {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
}

/* ==========================================
   GEO STATS
   ========================================== */
.geo-stats {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 15px;
    background: var(--bg-secondary);
    border-radius: var(--radius-sm);
    font-size: 12px;
    color: var(--text-secondary);
    font-family: 'Fira Code', monospace;
}

/* ==========================================
   HINT TEXT
   ========================================== */
.controls-hint {
    padding: 12px 15px;
    background: var(--bg-secondary);
    border-radius: var(--radius-sm);
    font-size: 12px;
    color: var(--text-secondary);
    text-align: center;
    margin-top: 10px;
}

@media (max-width: 768px) {
    .controls-hint {
        font-size: 11px;
        padding: 10px;
    }
    
    .controls-hint br {
        display: none;
    }
}

/* ==========================================
   STATUS BAR
   ========================================== */
.status-bar {
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 8px 20px;
    padding-bottom: max(8px, env(safe-area-inset-bottom, 8px));
    background: var(--primary-color);
    color: white;
    font-size: 12px;
    z-index: 100;
    flex-wrap: wrap;
    gap: 8px;
}

@media (max-width: 768px) {
    .status-bar {
        padding: 6px 12px;
        font-size: 11px;
    }
    
    .status-left,
    .status-right {
        gap: 12px;
    }
    
    #batteryIndicator {
        display: none;
    }
}

.status-left,
.status-right {
    display: flex;
    gap: 20px;
}

.status-item {
    display: flex;
    align-items: center;
    gap: 6px;
    opacity: 0.9;
}

/* ==========================================
   TOAST NOTIFICATIONS
   ========================================== */
.toast-container {
    position: fixed;
    top: calc(var(--header-height) + 20px);
    right: 20px;
    z-index: 1000;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.toast {
    padding: 12px 20px;
    background: var(--bg-glass);
    backdrop-filter: blur(10px);
    border-radius: 10px;
    box-shadow: var(--shadow-lg);
    border-left: 4px solid var(--accent-color);
    animation: toastIn 0.3s ease;
    max-width: 320px;
    color: var(--text-primary);
}

.toast.error {
    border-left-color: #ef4444;
}

.toast.success {
    border-left-color: #22c55e;
}

@keyframes toastIn {
    from {
        opacity: 0;
        transform: translateX(100px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

/* ==========================================
   SHORTCUTS OVERLAY
   ========================================== */
.shortcuts-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
    padding: 20px;
}

@media (max-width: 768px) {
    .shortcuts-overlay {
        padding: 10px;
        align-items: flex-end;
        padding-bottom: 40px;
    }
    
    .shortcuts-card {
        max-height: 80vh;
        width: 100%;
        border-radius: 20px 20px 10px 10px;
    }
    
    .shortcuts-grid {
        grid-template-columns: 1fr;
        gap: 8px;
    }
    
    .shortcut-item {
        padding: 12px 15px;
    }
}

.shortcuts-overlay.active {
    opacity: 1;
    visibility: visible;
}

.shortcuts-card {
    background: var(--panel-bg);
    border-radius: var(--radius);
    padding: 30px;
    max-width: 600px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
    box-shadow: var(--shadow-lg);
}

.shortcuts-card h2 {
    margin-bottom: 20px;
    color: var(--text-primary);
    text-align: center;
}

.shortcuts-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
    margin-bottom: 25px;
}

.shortcut-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 15px;
    background: var(--bg-secondary);
    border-radius: var(--radius-sm);
}

.shortcut-item > span:first-child {
    color: var(--text-primary);
    font-size: 14px;
}

.key {
    display: inline-block;
    padding: 3px 8px;
    background: var(--panel-bg);
    border: 1px solid var(--border-color);
    border-radius: 4px;
    font-size: 12px;
    font-family: 'Fira Code', monospace;
    color: var(--text-primary);
}

.close-shortcuts {
    width: 100%;
    justify-content: center;
    padding: 12px;
}

/* ==========================================
   PWA INSTALL PROMPT
   ========================================== */
.pwa-toast {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--panel-bg);
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    padding: 16px 20px;
    z-index: 10000;
    display: flex;
    align-items: center;
    max-width: 400px;
    animation: slideUp 0.4s ease;
}

.pwa-content {
    display: flex;
    align-items: center;
    gap: 15px;
    flex: 1;
}

.pwa-icon {
    font-size: 32px;
}

.pwa-text {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.pwa-text strong {
    font-size: 15px;
    color: var(--text-primary);
}

.pwa-text span {
    font-size: 13px;
    color: var(--text-secondary);
}

.pwa-btns {
    display: flex;
    gap: 8px;
}

.pwa-primary {
    padding: 8px 16px;
    background: var(--accent-color);
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    font-weight: 600;
    cursor: pointer;
    transition: opacity 0.2s;
}

.pwa-primary:hover {
    opacity: 0.9;
}

.pwa-secondary {
    padding: 8px 16px;
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.2s;
}

.pwa-secondary:hover {
    background: var(--bg-secondary);
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translate(-50%, 50px);
    }
    to {
        opacity: 1;
        transform: translate(-50%, 0);
    }
}

/* ==========================================
   PARAM INPUTS
   ========================================== */
.param-range {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px;
}

.param-range input {
    padding: 8px 12px;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 13px;
    color: var(--text-primary);
}

.scatter-hint {
    font-size: 13px;
    color: var(--text-secondary);
    margin-bottom: 10px;
    font-style: italic;
}

/* ==========================================
   MEASUREMENT CALCULATOR
   ========================================== */
.measurement-tools {
    background: var(--bg-secondary);
    border-radius: 10px;
    padding: 15px;
}

.measurement-hint {
    font-size: 12px;
    color: var(--text-secondary);
    margin-bottom: 10px;
}

.measurement-result-container {
    margin-top: 15px;
    padding: 15px;
    background: var(--bg-primary);
    border-radius: 8px;
    border-left: 4px solid var(--accent-color);
}

.measurement-result h4 {
    margin: 0 0 10px 0;
    color: var(--text-primary);
    font-size: 14px;
}

.result-value {
    font-size: 18px;
    font-weight: 600;
    color: var(--accent-color);
    margin-bottom: 8px;
    font-family: 'Fira Code', monospace;
}

.result-formula {
    font-size: 12px;
    color: var(--text-secondary);
    font-style: italic;
    margin-bottom: 8px;
}

.result-detail {
    font-size: 13px;
    color: var(--text-secondary);
}

.measurement-buttons {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 8px;
}

.calc-btn {
    padding: 10px;
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 13px;
    color: var(--text-primary);
    cursor: pointer;
    transition: all 0.2s;
}

.calc-btn:hover {
    background: var(--accent-color);
    color: white;
    border-color: var(--accent-color);
}

/* ==========================================
   TRIANGLE CENTERS PANEL
   ========================================== */
.triangle-centers-panel {
    position: absolute;
    top: 70px;
    left: 20px;
    width: 280px;
    max-height: calc(100vh - 200px);
    background: var(--bg-glass);
    backdrop-filter: blur(12px);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
    z-index: 55;
    display: none;
    overflow-y: auto;
}

.triangle-centers-panel.active {
    display: block;
}

.triangle-centers-controls {
    background: var(--bg-secondary);
    border-radius: 10px;
    padding: 15px;
}

.centers-hint {
    font-size: 12px;
    color: var(--text-secondary);
    margin-bottom: 10px;
}

.center-item {
    display: flex;
    justify-content: space-between;
    padding: 10px 0;
    border-bottom: 1px solid var(--border-color);
}

.center-item:last-child {
    border-bottom: none;
}

.center-name {
    font-weight: 600;
    color: var(--text-primary);
    font-size: 13px;
}

.center-coords {
    font-family: 'Fira Code', monospace;
    font-size: 12px;
    color: var(--accent-color);
}

/* ==========================================
   TUTORIAL PANEL
   ========================================== */
.tutorial-panel {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
}

.tutorial-panel.active {
    opacity: 1;
    visibility: visible;
}

.tutorial-card {
    background: var(--panel-bg);
    border-radius: var(--radius);
    padding: 30px;
    max-width: 600px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
    box-shadow: var(--shadow-lg);
}

.tutorial-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding-bottom: 15px;
    border-bottom: 1px solid var(--border-color);
}

.tutorial-header h2 {
    margin: 0;
    color: var(--text-primary);
}

.tutorial-section {
    margin-bottom: 25px;
}

.tutorial-section h3 {
    color: var(--accent-color);
    margin-bottom: 10px;
    font-size: 1.1rem;
}

.tutorial-section p {
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 10px;
}

.tutorial-section ul {
    padding-left: 20px;
}

.tutorial-section li {
    color: var(--text-secondary);
    margin-bottom: 8px;
    line-height: 1.5;
}

.tutorial-section strong {
    color: var(--text-primary);
}

/* ==========================================
   CHEAT SHEET PANEL
   ========================================== */
.cheat-sheet-panel {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 2000;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s ease;
}

.cheat-sheet-panel.active {
    opacity: 1;
    visibility: visible;
}

.cheat-sheet-card {
    background: var(--panel-bg);
    border-radius: var(--radius);
    padding: 30px;
    max-width: 700px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
    box-shadow: var(--shadow-lg);
}

.cheat-sheet-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding-bottom: 15px;
    border-bottom: 1px solid var(--border-color);
}

.cheat-sheet-header h2 {
    margin: 0;
    color: var(--text-primary);
}

.formula-category {
    margin-bottom: 25px;
}

.formula-category h3 {
    color: var(--accent-color);
    margin-bottom: 15px;
    font-size: 1.1rem;
    padding-bottom: 8px;
    border-bottom: 2px solid var(--border-color);
}

.formula-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 0;
    border-bottom: 1px solid var(--border-color);
}

.formula-item:last-child {
    border-bottom: none;
}

.formula-name {
    font-weight: 600;
    color: var(--text-primary);
    font-size: 14px;
}

.formula {
    font-family: 'Fira Code', monospace;
    font-size: 14px;
    color: var(--accent-color);
    background: var(--bg-secondary);
    padding: 6px 12px;
    border-radius: 6px;
}

/* Panel Close Button */
.panel-close {
    width: 32px;
    height: 32px;
    border: none;
    background: var(--bg-secondary);
    border-radius: 50%;
    font-size: 20px;
    color: var(--text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s;
}

.panel-close:hover {
    background: #ef4444;
    color: white;
}

/* Panel Header */
.panel-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 20px;
    border-bottom: 1px solid var(--border-color);
    font-weight: 600;
    color: var(--text-primary);
}

.panel-content {
    padding: 20px;
}

.panel-placeholder {
    text-align: center;
    color: var(--text-secondary);
    font-style: italic;
    padding: 20px;
}

.panel-hint {
    font-size: 12px;
    color: var(--text-secondary);
    margin-bottom: 12px;
}

/* ==========================================
   UTILITIES
   ========================================== */
.hidden {
    display: none !important;
}

.fade-in {
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

/* ==========================================
   SEO CONTENT SECTION
   ========================================== */
.seo-content-section {
    position: relative;
    background: var(--bg-primary);
    padding: 60px 20px;
    max-width: 1000px;
    margin: 0 auto;
}

.breadcrumb-nav {
    margin-bottom: 30px;
    padding: 12px 20px;
    background: var(--bg-secondary);
    border-radius: 10px;
}

.breadcrumb-nav ol {
    display: flex;
    gap: 10px;
    list-style: none;
    margin: 0;
    padding: 0;
}

.breadcrumb-nav li:not(:last-child)::after {
    content: '›';
    margin-left: 10px;
    color: var(--text-secondary);
}

.breadcrumb-nav a {
    color: var(--accent-color);
    text-decoration: none;
}

.breadcrumb-nav a:hover {
    text-decoration: underline;
}

.breadcrumb-nav [aria-current="page"] span {
    color: var(--text-secondary);
}

/* AI SUMMARY BOX */
.ai-summary-box {
    background: linear-gradient(135deg, #4c63c7 0%, #5a3d8a 100%);
    color: #ffffff;
    padding: 25px 30px;
    border-radius: var(--radius);
    margin-bottom: 40px;
    text-shadow: 0 1px 2px rgba(0,0,0,0.3);
}

.ai-summary-box .ai-summary-title {
    color: #ffffff;
    margin-bottom: 15px;
    font-size: 1.3rem;
    font-weight: 700;
    text-shadow: 0 1px 2px rgba(0,0,0,0.3);
}

.ai-summary-box h2 {
    color: #ffffff;
    margin-bottom: 15px;
    font-size: 1.3rem;
    text-shadow: 0 1px 2px rgba(0,0,0,0.3);
}

.ai-summary-box ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.ai-summary-box li {
    margin-bottom: 8px;
    padding-left: 20px;
    position: relative;
}

.ai-summary-box li::before {
    content: '✓';
    position: absolute;
    left: 0;
    font-weight: bold;
}

.ai-summary-box li:last-child {
    margin-bottom: 0;
}

/* TRUST BADGES */
.trust-badges {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 20px;
    margin-bottom: 50px;
    padding: 20px;
    background: var(--bg-secondary);
    border-radius: var(--radius);
}

.trust-badge-item {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
    font-weight: 600;
    color: var(--text-primary);
}

.trust-badge-item .icon {
    font-size: 20px;
}

/* ARTICLE STYLES */
.seo-content-section article h1 {
    font-size: 2rem;
    margin-bottom: 20px;
    color: var(--text-primary);
}

.lead-text {
    font-size: 1.1rem;
    line-height: 1.8;
    color: var(--text-secondary);
    margin-bottom: 30px;
}

.intro-box {
    background: var(--bg-secondary);
    padding: 30px;
    border-radius: var(--radius);
    margin-bottom: 40px;
    border-left: 4px solid var(--accent-color);
}

.intro-box h2 {
    margin-bottom: 15px;
    color: var(--text-primary);
}

.intro-box p {
    color: var(--text-secondary);
    margin-bottom: 15px;
    line-height: 1.7;
}

.intro-box p:last-child {
    margin-bottom: 0;
}

/* FEATURE GRID */
.seo-content-section h2 {
    font-size: 1.5rem;
    margin: 40px 0 25px;
    color: var(--text-primary);
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
    margin-bottom: 40px;
}

.feature-card {
    background: var(--bg-secondary);
    padding: 25px;
    border-radius: var(--radius);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.feature-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow);
}

.feature-card h3 {
    font-size: 1.1rem;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.feature-card p {
    font-size: 0.95rem;
    line-height: 1.6;
    color: var(--text-secondary);
}

/* COMPARISON TABLE */
.comparison-table {
    width: 100%;
    border-collapse: collapse;
    margin-bottom: 40px;
    background: var(--bg-secondary);
    border-radius: var(--radius);
    overflow: hidden;
}

.comparison-table th,
.comparison-table td {
    padding: 15px 20px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.comparison-table th {
    background: var(--primary-color);
    color: white;
    font-weight: 600;
    font-size: 0.9rem;
}

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

.comparison-table .check {
    color: #22c55e;
    font-weight: bold;
}

.comparison-table .cross {
    color: #ef4444;
}

/* USE CASE GRID */
.use-case-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin-bottom: 40px;
}

.use-case-card {
    background: var(--bg-secondary);
    padding: 25px;
    border-radius: var(--radius);
}

.use-case-card h4 {
    font-size: 1rem;
    margin-bottom: 12px;
    color: var(--text-primary);
}

.use-case-card p {
    font-size: 0.9rem;
    line-height: 1.6;
    color: var(--text-secondary);
}

/* HOW-TO SECTION */
.howto-steps {
    background: var(--bg-secondary);
    padding: 30px;
    border-radius: var(--radius);
    margin-bottom: 40px;
}

.howto-steps h3 {
    margin-bottom: 20px;
    color: var(--text-primary);
}

.howto-steps ol {
    padding-left: 20px;
}

.howto-steps li {
    margin-bottom: 15px;
    line-height: 1.7;
    color: var(--text-secondary);
}

.howto-steps strong {
    color: var(--text-primary);
}

/* EDUCATIONAL ALIGNMENT */
.educational-alignment {
    background: var(--bg-secondary);
    padding: 30px;
    border-radius: var(--radius);
    margin-bottom: 40px;
}

.educational-alignment h2 {
    margin-top: 0;
}

.educational-alignment ul {
    list-style: none;
    padding: 0;
}

.educational-alignment li {
    padding: 12px 0;
    border-bottom: 1px solid var(--border-color);
    line-height: 1.6;
    color: var(--text-secondary);
}

.educational-alignment li:last-child {
    border-bottom: none;
}

.educational-alignment li strong {
    color: var(--text-primary);
}

/* AUTHOR CARD (EEAT) */
.author-card {
    display: flex;
    gap: 25px;
    padding: 30px;
    background: var(--bg-secondary);
    border-radius: var(--radius);
    margin-bottom: 40px;
}

.author-card img {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    object-fit: cover;
    border: 3px solid var(--accent-color);
    flex-shrink: 0;
}

.author-card h3 {
    font-size: 1.2rem;
    margin-bottom: 5px;
    color: var(--text-primary);
}

.author-card .author-title {
    font-size: 0.9rem;
    color: var(--accent-color);
    font-weight: 600;
    margin-bottom: 12px;
}

.author-card .author-bio {
    font-size: 0.95rem;
    line-height: 1.6;
    color: var(--text-secondary);
    margin-bottom: 15px;
}

.author-links {
    display: flex;
    gap: 15px;
}

.author-links a {
    color: var(--accent-color);
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
}

.author-links a:hover {
    text-decoration: underline;
}

/* VERIFICATION SECTION */
.verification-section,
.verification-box {
    background: var(--bg-secondary);
    padding: 30px;
    border-radius: var(--radius);
    margin-bottom: 40px;
}

.verification-section h2,
.verification-box h2 {
    margin-top: 0;
}

.verification-section ul,
.verification-box ul {
    list-style: none;
    padding: 0;
}

.verification-section li,
.verification-box li {
    padding: 10px 0 10px 30px;
    position: relative;
    line-height: 1.6;
    color: var(--text-secondary);
}

.verification-section li::before,
.verification-box li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: #22c55e;
    font-weight: bold;
}

.verification-date {
    margin-top: 20px;
    font-size: 0.9rem;
    color: var(--text-secondary);
    font-style: italic;
}

/* FAQ SECTION */
.faq-section {
    margin-bottom: 40px;
}

.faq-container {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.faq-item {
    background: var(--bg-secondary);
    border-radius: 10px;
    overflow: hidden;
}

.faq-question {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 25px;
    cursor: pointer;
    font-weight: 600;
    font-size: 1rem;
    color: var(--text-primary);
    list-style: none;
    user-select: none;
}

.faq-question::-webkit-details-marker {
    display: none;
}

.faq-icon {
    width: 24px;
    height: 24px;
    position: relative;
    transition: transform 0.3s ease;
}

.faq-icon::before,
.faq-icon::after {
    content: '';
    position: absolute;
    background: var(--accent-color);
    transition: transform 0.3s ease;
}

.faq-icon::before {
    width: 12px;
    height: 2px;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

.faq-icon::after {
    width: 2px;
    height: 12px;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

.faq-item[open] .faq-icon {
    transform: rotate(45deg);
}

.faq-answer {
    padding: 0 25px 20px;
    line-height: 1.7;
    color: var(--text-secondary);
}

.faq-answer strong {
    color: var(--text-primary);
}

/* RELATED TOOLS */
.related-tools {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
    margin-bottom: 40px;
}

.tool-card {
    display: flex;
    align-items: center;
    gap: 15px;
    padding: 20px;
    background: var(--bg-secondary);
    border-radius: var(--radius);
    text-decoration: none;
    transition: all 0.2s ease;
    border: 2px solid transparent;
}

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

.tool-card .tool-icon,
.tool-card .icon {
    font-size: 28px;
}

.tool-card h4 {
    font-size: 1rem;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.tool-card span {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

/* LEGAL DISCLAIMER FOOTER */
.legal-disclaimer-footer,
.legal-disclaimer {
    background: var(--primary-color);
    color: rgba(255,255,255,0.8);
    padding: 40px 20px;
    text-align: center;
}

.legal-disclaimer-footer > div,
.legal-disclaimer > div {
    max-width: 900px;
    margin: 0 auto;
}

.legal-disclaimer-footer strong,
.legal-disclaimer strong {
    color: white;
    display: block;
    margin-bottom: 15px;
}

.legal-disclaimer-footer p,
.legal-disclaimer p {
    font-size: 0.9rem;
    line-height: 1.7;
    margin-bottom: 15px;
}

.legal-disclaimer-footer a,
.legal-disclaimer a {
    color: var(--accent-color);
    text-decoration: none;
}

.legal-disclaimer-footer a:hover,
.legal-disclaimer a:hover {
    text-decoration: underline;
}

.disclaimer-note {
    font-size: 0.85rem;
    color: rgba(255,255,255,0.6);
    font-style: italic;
}

.footer-links,
.legal-links {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin: 25px 0;
    flex-wrap: wrap;
}

.legal-links a {
    color: var(--accent-color);
    text-decoration: none;
}

.copyright {
    font-size: 0.85rem;
    color: rgba(255,255,255,0.5);
}

/* ==========================================
   SIDEBAR NAVIGATION
   ========================================== */
.sidebar {
    position: fixed;
    top: 0;
    left: 0;
    width: 280px;
    height: 100vh;
    background: var(--panel-bg);
    border-right: 1px solid var(--border-color);
    z-index: 1000;
    transform: translateX(-100%);
    transition: transform 0.3s ease;
    overflow-y: auto;
}

.sidebar.active {
    transform: translateX(0);
}

.sidebar-header {
    padding: 20px;
    border-bottom: 1px solid var(--border-color);
}

.sidebar-logo {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--text-primary);
}

.sidebar-tagline {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-top: 5px;
}

.sidebar-nav {
    padding: 15px;
}

.nav-section {
    margin-bottom: 20px;
}

.nav-section-title {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--text-secondary);
    margin-bottom: 10px;
    padding: 0 10px;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 15px;
    color: var(--text-primary);
    text-decoration: none;
    border-radius: var(--radius-sm);
    transition: all 0.2s;
    margin-bottom: 4px;
}

.nav-item:hover {
    background: var(--bg-secondary);
}

.nav-item.active {
    background: var(--accent-color);
    color: white;
}

.nav-item .icon {
    font-size: 18px;
    width: 24px;
    text-align: center;
}

.sidebar-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0,0,0,0.5);
    z-index: 999;
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s;
}

.sidebar-overlay.active {
    opacity: 1;
    visibility: visible;
}

/* ==========================================
   HEADER
   ========================================== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background: var(--panel-bg);
    border-bottom: 1px solid var(--border-color);
    z-index: 100;
}

.header-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
    padding: 0 20px;
    max-width: 1400px;
    margin: 0 auto;
}

/* Header & Nav — primary styles in css/style.css */
/* geometry.css provides only layout overrides specific to the geometry page */

.logo-text h1 {
    font-size: 1.3rem;
    color: var(--text-primary);
    margin: 0;
}

.logo-text .tagline {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    color: var(--text-primary);
    cursor: pointer;
    padding: 8px;
}

/* ==========================================
   CALCULATION LOADING
   ========================================== */
.calculation-loading {
    position: fixed;
    top: var(--header-height);
    left: 0;
    right: 0;
    background: var(--accent-color);
    color: white;
    text-align: center;
    padding: 8px;
    font-size: 14px;
    z-index: 99;
    transform: translateY(-100%);
    transition: transform 0.3s;
}

.calculation-loading.active {
    transform: translateY(0);
}

/* ==========================================
   TECHNICAL FOOTER
   ========================================== */
.footer {
    background: var(--bg-secondary);
    padding: 40px 20px;
    border-top: 1px solid var(--border-color);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
    max-width: 1000px;
    margin: 0 auto;
}

.footer-col h4 {
    font-size: 0.9rem;
    color: var(--text-primary);
    margin-bottom: 15px;
}

.footer-col ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.footer-col li {
    margin-bottom: 8px;
}

.footer-col a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.2s;
}

.footer-col a:hover {
    color: var(--accent-color);
}

/* ==========================================
   RESPONSIVE DESIGN
   ========================================== */
@media (max-width: 768px) {
    .hide-mobile {
        display: none !important;
    }
    
    :root {
        --header-height: 60px;
    }
    
    .geometry-workspace {
        top: 60px;
    }
    
    .geo-toolbar-overlay {
        top: 5px;
        left: 5px;
        right: 5px;
        padding: 8px;
        gap: 5px;
        flex-wrap: wrap;
    }
    
    .action-btn {
        padding: 6px 10px;
        font-size: 12px;
    }
    
    .info-panel {
        top: 60px;
        right: 5px;
        left: 5px;
        width: auto;
        max-height: 40vh;
    }
    
    .controls-overlay {
        bottom: 50px;
        left: 5px;
        right: 5px;
        max-height: 45vh;
    }
    
    .zoom-controls {
        bottom: 10px;
    }
    
    .zoom-btn {
        width: 36px;
        height: 36px;
        font-size: 16px;
    }
    
    .tool-btn {
        min-width: 50px;
        padding: 8px;
    }
    
    .tool-btn span:first-child {
        font-size: 16px;
    }
    
    .tool-btn span:last-child,
    .tool-btn .shortcut {
        font-size: 9px;
    }
    
    .geo-toolbar {
        gap: 5px;
    }
    
    .slicer-inputs {
        flex-direction: column;
    }
    
    .param-range {
        grid-template-columns: 1fr;
    }
    
    .status-bar {
        padding: 6px 10px;
        font-size: 10px;
    }
    
    .shortcuts-card {
        padding: 20px;
        margin: 10px;
    }
    
    .shortcuts-grid {
        grid-template-columns: 1fr;
    }
    
    /* SEO Mobile */
    .seo-content-section {
        padding: 40px 15px;
    }
    
    .author-card {
        flex-direction: column;
        text-align: center;
        align-items: center;
    }
    
    .author-links {
        justify-content: center;
    }
    
    .comparison-table {
        font-size: 0.85rem;
    }
    
    .comparison-table th,
    .comparison-table td {
        padding: 10px 12px;
    }
    
    .ai-summary-box {
        padding: 20px;
    }
    
    .trust-badges {
        padding: 15px;
    }
    
    /* New Panels Mobile */
    .triangle-centers-panel {
        top: 60px;
        left: 5px;
        right: 5px;
        width: auto;
        max-height: 40vh;
    }
    
    .measurement-panel {
        top: 60px;
        left: 5px;
        right: 5px;
        width: auto;
        max-height: 40vh;
    }
    
    .measurement-buttons {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .tutorial-card,
    .cheat-sheet-card {
        padding: 20px;
        margin: 10px;
        max-height: 85vh;
    }
    
    .formula-item {
        flex-direction: column;
        align-items: flex-start;
        gap: 5px;
    }
    
    .formula {
        font-size: 12px;
        padding: 4px 8px;
    }
    
    /* Navigation Mobile */
    .desktop-nav {
        display: none;
    }
    
    .mobile-menu-btn {
        display: block;
    }
    
    .sidebar {
        width: 260px;
    }
    
    .footer-content {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 480px) {
    .mode-tabs {
        flex-direction: column;
    }
    
    .geo-toolbar-overlay {
        flex-direction: column;
    }
    
    .func-input-group {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .func-input {
        width: 100%;
    }
    
    .slider-group {
        flex-wrap: wrap;
    }
    
    .zoom-controls {
        gap: 5px;
    }
    
    .zoom-btn {
        width: 32px;
        height: 32px;
        font-size: 14px;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
        gap: 20px;
    }
}

/* ==========================================
   ACCESSIBILITY ENHANCEMENTS
   ========================================== */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus styles for keyboard navigation */
.action-btn:focus,
.tool-btn:focus,
.tab-btn:focus,
.zoom-btn:focus,
.slider:focus,
.func-input:focus,
.nav-link:focus,
.nav-item:focus {
    outline: 2px solid var(--accent-color);
    outline-offset: 2px;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    .action-btn,
    .tool-btn,
    .tab-btn {
        border-width: 2px;
    }
    
    .info-panel,
    .controls-overlay {
        border: 2px solid currentColor;
    }
}

/* ==========================================
   FLOATING CONTROLS TOGGLE
   ========================================== */
.floating-controls-toggle {
    position: absolute;
    bottom: 90px;
    left: 50%;
    transform: translateX(-50%) translateY(20px);
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    background: var(--accent-color);
    color: white;
    border: none;
    border-radius: 25px;
    font-size: 14px;
    font-weight: 600;
    cursor: pointer;
    box-shadow: 0 4px 15px rgba(0,0,0,0.3);
    z-index: 70;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease, transform 0.3s ease;
    will-change: opacity, transform;
}

.floating-controls-toggle:hover {
    filter: brightness(1.1);
    box-shadow: 0 6px 20px rgba(0,0,0,0.4);
}

.floating-controls-toggle.visible,
.controls-overlay.collapsed ~ .floating-controls-toggle {
    opacity: 1;
    pointer-events: auto;
    transform: translateX(-50%) translateY(0);
}

.floating-controls-toggle svg {
    width: 20px;
    height: 20px;
    flex-shrink: 0;
}

@media (max-width: 768px) {
    .floating-controls-toggle {
        bottom: 70px;
        padding: 10px 18px;
        font-size: 13px;
    }
    
    .floating-controls-toggle span {
        display: none;
    }
}

/* ==========================================
   SKIP LINKS (ACCESSIBILITY)
   ========================================== */
.skip-link {
    position: absolute;
    top: -100%;
    left: 50%;
    transform: translateX(-50%);
    background: var(--accent-color);
    color: white;
    padding: 12px 24px;
    border-radius: 0 0 var(--radius) var(--radius);
    font-weight: 600;
    text-decoration: none;
    z-index: 10000;
    transition: top 0.2s;
}

.skip-link:focus {
    top: 0;
    outline: 2px solid white;
    outline-offset: -2px;
}

/* ==========================================
   TABLE WRAPPER (RESPONSIVE)
   ========================================== */
.table-wrapper {
    overflow-x: auto;
    margin-bottom: 40px;
    border-radius: var(--radius);
    -webkit-overflow-scrolling: touch;
}

.table-wrapper .comparison-table {
    margin-bottom: 0;
    min-width: 500px;
}

/* ==========================================
   MEASUREMENT PANEL SPECIFIC STYLES
   ========================================== */
.measurement-panel {
    position: absolute;
    top: 70px;
    left: 20px;
    width: 280px;
    max-height: calc(100vh - 200px);
    background: var(--bg-glass);
    backdrop-filter: blur(12px);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
    z-index: 55;
    display: none;
    overflow-y: auto;
}

.measurement-panel.active {
    display: block;
}

.measurement-panel .panel-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 20px;
    border-bottom: 1px solid var(--border-color);
    font-weight: 600;
    color: var(--text-primary);
}

.measurement-panel .panel-content {
    padding: 20px;
}

/* ==========================================
   IMPROVED FOCUS STYLES
   ========================================== */
button:focus-visible,
a:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
    outline: 2px solid var(--accent-color);
    outline-offset: 2px;
}

/* ==========================================
   LOADING STATE ANIMATION
   ========================================== */
@keyframes pulse-loading {
    0%, 100% { opacity: 0.6; }
    50% { opacity: 1; }
}

.calculation-loading span {
    animation: pulse-loading 1.5s ease-in-out infinite;
}

/* ==========================================
   PRINT STYLES
   ========================================== */
@media print {
    .geometry-workspace,
    .shortcuts-overlay,
    .pwa-toast,
    .sidebar,
    .header,
    .mobile-menu-btn,
    .geo-toolbar-overlay,
    .controls-overlay,
    .zoom-controls,
    .info-panel,
    .triangle-centers-panel,
    .measurement-panel,
    .tutorial-panel,
    .cheat-sheet-panel {
        display: none !important;
    }
    
    .seo-content-section {
        position: static;
        max-width: 100%;
        padding: 20px;
    }
    
    body {
        background: white;
        color: black;
    }
    
    .ai-summary-box {
        background: #f0f0f0 !important;
        color: black !important;
        border: 1px solid #ccc;
    }
    
    .ai-summary-box h2 {
        color: black !important;
    }
    
    .feature-card,
    .use-case-card {
        border: 1px solid #ccc;
        break-inside: avoid;
    }
    
    .faq-item {
        border: 1px solid #ccc;
        break-inside: avoid;
    }
}

/* ==========================================
   UNIFIED FOOTER STYLES
   ========================================== */
.site-footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border-color);
    margin-top: 40px;
}

/* Legal Disclaimer Section */
.footer-legal-section {
    padding: 30px 20px;
    max-width: 900px;
    margin: 0 auto;
    text-align: center;
    border-bottom: 1px solid var(--border-color);
}

.footer-legal-section strong {
    display: block;
    font-size: 16px;
    color: var(--text-primary);
    margin-bottom: 15px;
}

.footer-legal-section p {
    font-size: 13px;
    line-height: 1.6;
    color: var(--text-secondary);
    margin-bottom: 10px;
}

.footer-legal-section .disclaimer-note {
    font-size: 12px;
    font-style: italic;
}

.footer-legal-links {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-top: 20px;
    flex-wrap: wrap;
}

.footer-legal-links a {
    color: var(--accent-color);
    text-decoration: none;
    font-size: 13px;
    font-weight: 500;
    transition: opacity 0.2s;
}

.footer-legal-links a:hover {
    opacity: 0.8;
    text-decoration: underline;
}

/* Navigation Links Section */
.site-footer .footer-content {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
    max-width: 1100px;
    margin: 0 auto;
    padding: 40px 20px;
}

.site-footer .footer-col h4 {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 15px;
}

.site-footer .footer-col ul {
    list-style: none;
    padding: 0;
    margin: 0;
}

.site-footer .footer-col li {
    margin-bottom: 8px;
}

.site-footer .footer-col a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 13px;
    transition: color 0.2s;
}

.site-footer .footer-col a:hover {
    color: var(--accent-color);
}

/* Copyright Bar */
.footer-copyright-bar {
    background: var(--bg-primary);
    padding: 15px 20px;
    text-align: center;
    border-top: 1px solid var(--border-color);
}

.footer-copyright-bar p {
    font-size: 12px;
    color: var(--text-secondary);
    margin: 0;
}

/* Footer Responsive */
@media (max-width: 768px) {
    .site-footer .footer-content {
        grid-template-columns: repeat(2, 1fr);
        gap: 20px;
        padding: 30px 15px;
    }
    
    .footer-legal-section {
        padding: 20px 15px;
    }
    
    .footer-legal-links {
        gap: 15px;
    }
}

@media (max-width: 480px) {
    .site-footer .footer-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .footer-legal-links {
        flex-direction: column;
        gap: 10px;
    }
}

/* ==========================================================================
   THEME-AWARE LINK COLORS (all tool pages)
   ========================================================================== */

/* Light theme fallback (default) */
a {
  color: #0066cc;
}

/* Dark theme – bright readable blue */
[data-theme="dark"] a {
  color: #5dade2;
}

/* Solar theme – gold, matches the solar palette */
[data-theme="solar"] a {
  color: #ffd700;
}

/* Keep navigation links untouched – they already have their own styles */
header a,
.sidebar a,
.nav-link,
.breadcrumb-nav a,
.legal-links a,
.footer a {
  /* inherited or already styled – reset so the above doesn't override them */
  color: inherit;
}

/* Restore footer and legal link colors */
.footer a {
  color: var(--text-secondary);
}
.legal-links a {
  color: var(--link-color); /* or use --accent-secondary if available */
}

/* Hover state */
a:hover {
  text-decoration: underline;
  opacity: 0.9;
}