/**
 * Spreadsheet Tool - Optimized Styles v2.0
 * Performance-focused with GPU acceleration for grid rendering
 */

:root {
    /* Core Colors */
    --primary-color: #3b82f6;
    --primary-hover: #2563eb;
    --primary-light: rgba(59, 130, 246, 0.12);
    --primary-glow: rgba(59, 130, 246, 0.35);
    --secondary-color: #8b5cf6;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --warning-color: #f59e0b;
    --info-color: #0ea5e9;
    
    /* Light Theme */
    --dark-bg: #0f172a;
    --dark-card: #1e293b;
    --dark-text: #f1f5f9;
    --light-bg: #f8fafc;
    --light-card: #ffffff;
    --light-text: #1e293b;
    
    /* Enhanced Layout */
    --border-radius: 10px;
    --border-radius-sm: 6px;
    --border-radius-lg: 16px;
    --box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.08), 0 2px 4px -1px rgba(0, 0, 0, 0.04);
    --box-shadow-lg: 0 10px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.05);
    --box-shadow-inner: inset 0 2px 4px rgba(0, 0, 0, 0.04);
    
    /* GPU-Optimized Transitions */
    --transition-fast: 0.15s cubic-bezier(0.4, 0, 0.2, 1);
    --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    
    /* Spreadsheet specific - Enhanced */
    --grid-border: #e2e8f0;
    --grid-bg: #ffffff;
    --header-bg: linear-gradient(180deg, #f8fafc 0%, #f1f5f9 100%);
    --header-bg-solid: #f3f4f6;
    --cell-selected: rgba(59, 130, 246, 0.15);
    --cell-highlight: rgba(59, 130, 246, 0.06);
    --cell-editing: rgba(59, 130, 246, 0.08);
    --toolbar-bg: rgba(248, 250, 252, 0.95);
    --formula-bg: rgba(241, 245, 249, 0.9);
    
    /* Glass Effect */
    --glass-blur: blur(12px);
    --glass-bg: rgba(255, 255, 255, 0.85);
    --glass-border: rgba(255, 255, 255, 0.3);
}

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

html {
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: 'Inter', 'Segoe UI', system-ui, -apple-system, sans-serif;
    background: linear-gradient(135deg, #f8fafc 0%, #e0f2fe 50%, #f0f9ff 100%);
    color: var(--light-text);
    transition: background var(--transition), color var(--transition-fast);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

body.dark-mode {
    background: linear-gradient(135deg, #0f172a 0%, #1e3a5f 50%, #1e1b4b 100%);
    color: var(--dark-text);
    --grid-border: #374155;
    --grid-bg: #1e293b;
    --header-bg: linear-gradient(180deg, #334155 0%, #1e293b 100%);
    --header-bg-solid: #334155;
    --cell-selected: rgba(139, 92, 246, 0.25);
    --cell-highlight: rgba(139, 92, 246, 0.12);
    --cell-editing: rgba(139, 92, 246, 0.15);
    --toolbar-bg: rgba(30, 41, 59, 0.95);
    --formula-bg: rgba(15, 23, 42, 0.9);
    --glass-bg: rgba(30, 41, 59, 0.85);
    --glass-border: rgba(255, 255, 255, 0.08);
}

.container {
    max-width: 1440px;
    margin: 0 auto;
    padding: 20px;
    flex: 1;
}

/* Header Styles - Glass Effect */
header {
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.08), 0 1px 2px rgba(0, 0, 0, 0.04);
    border-bottom: 1px solid var(--glass-border);
    position: sticky;
    top: 0;
    z-index: 100;
    transition: background var(--transition-fast), border-color var(--transition-fast);
}

.dark-mode header {
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
}

.header-container {
    max-width: 1440px;
    margin: 0 auto;
    padding: 14px 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo-container {
    display: flex;
    align-items: center;
}

.logo-container a {
    display: flex;
    align-items: center;
    text-decoration: none;
    gap: 12px;
}

.logo {
    height: 38px;
    transition: transform var(--transition);
}

.logo-container a:hover .logo {
    transform: scale(1.05) translateZ(0);
}

.site-title {
    font-size: 22px;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -0.02em;
}

.nav-actions {
    display: flex;
    gap: 12px;
}

#theme-btn {
    background: var(--light-card);
    border: 1px solid var(--grid-border);
    font-size: 16px;
    cursor: pointer;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition);
    color: var(--light-text);
    box-shadow: var(--box-shadow);
}

.dark-mode #theme-btn {
    color: var(--dark-text);
    background: var(--dark-card);
    border-color: var(--grid-border);
}

#theme-btn:hover {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    color: white;
    border-color: transparent;
    transform: rotate(20deg) scale(1.08) translateZ(0);
    box-shadow: 0 4px 14px var(--primary-glow);
}

/* Page Title - Enhanced */
.page-title {
    text-align: center;
    margin: 24px 0;
    animation: slideUp 0.5s ease-out;
}

@keyframes slideUp {
    from { opacity: 0; transform: translateY(16px); }
    to { opacity: 1; transform: translateY(0); }
}

.page-title h1 {
    font-size: 32px;
    font-weight: 700;
    margin-bottom: 8px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    letter-spacing: -0.03em;
}

.page-title p {
    font-size: 16px;
    color: #64748b;
    font-weight: 400;
}

.dark-mode .page-title p {
    color: #94a3b8;
}

/* Spreadsheet Container - Performance Optimized */
.spreadsheet-container {
    background: var(--light-card);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--box-shadow-lg);
    border: 1px solid var(--grid-border);
    margin: 0 auto;
    position: relative;
    display: flex;
    flex-direction: column;
    height: 72vh;
    overflow: hidden;
    min-height: 500px;
    --grid-font-size: 13px;
    transition: box-shadow var(--transition), border-color var(--transition-fast);
    /* GPU optimization for grid */
    transform: translateZ(0);
    will-change: contents;
    contain: layout style;
}

.spreadsheet-container:hover {
    box-shadow: var(--box-shadow-lg), 0 0 0 1px var(--primary-color);
}

.dark-mode .spreadsheet-container {
    background: var(--dark-card);
}

/* Crosshair hover lines - GPU optimized */
.hover-line {
    position: absolute;
    background: var(--primary-color);
    opacity: 0;
    transition: opacity 60ms linear;
    pointer-events: none;
    z-index: 5;
    will-change: opacity;
}
.hover-line.h { height: 1px; width: 100%; left: 0; }
.hover-line.v { width: 1px; height: 100%; top: 0; }

/* Spreadsheet Grid - Performance Critical */
#spreadsheet {
    flex: 1;
    min-height: 300px;
    position: relative;
    cursor: crosshair;
    /* GPU layer for smooth scrolling */
    transform: translateZ(0);
    will-change: scroll-position;
    contain: strict;
}

/* Handsontable GPU Optimization */
.spreadsheet-container .handsontable {
    transform: translateZ(0);
    backface-visibility: hidden;
}

.spreadsheet-container .handsontable.ht_master {
    height: 100% !important;
}
.spreadsheet-container .handsontable.ht_master .wtHolder {
    height: 100% !important;
    /* Smooth scrolling */
    scroll-behavior: smooth;
    -webkit-overflow-scrolling: touch;
}
.spreadsheet-container .handsontable:not(.ht_master) {
    height: auto !important;
}
.spreadsheet-container .handsontable:not(.ht_master) .wtHolder {
    height: auto !important;
}

/* Toolbar Styles - Enhanced */
.toolbar {
    display: flex;
    padding: 10px 14px;
    background: var(--toolbar-bg);
    backdrop-filter: var(--glass-blur);
    border-bottom: 1px solid var(--grid-border);
    flex-wrap: wrap;
    gap: 8px;
    align-items: center;
}

.toolbar-group {
    display: flex;
    gap: 4px;
    padding-right: 14px;
    border-right: 1px solid var(--grid-border);
    align-items: center;
}

.toolbar-group:last-child {
    border-right: none;
    padding-right: 0;
}

.toolbar-btn {
    background: transparent;
    border: none;
    width: 34px;
    height: 34px;
    border-radius: var(--border-radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--light-text);
    transition: all var(--transition-fast);
    position: relative;
}

.dark-mode .toolbar-btn {
    color: var(--dark-text);
}

.toolbar-btn:hover {
    background: var(--primary-light);
    color: var(--primary-color);
    transform: translateY(-1px) translateZ(0);
}

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

/* Toolbar btn ripple effect */
.toolbar-btn::after {
    content: '';
    position: absolute;
    inset: 0;
    border-radius: inherit;
    background: radial-gradient(circle, var(--primary-color) 0%, transparent 70%);
    opacity: 0;
    transform: scale(0.5);
    transition: opacity var(--transition-fast), transform var(--transition-fast);
}

.toolbar-btn:active::after {
    opacity: 0.15;
    transform: scale(1.2);
}

.toolbar-select {
    padding: 6px 10px;
    border-radius: var(--border-radius-sm);
    border: 1px solid var(--grid-border);
    background: var(--light-card);
    color: var(--light-text);
    font-size: 13px;
    cursor: pointer;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.toolbar-select:hover {
    border-color: var(--primary-color);
}

.toolbar-select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px var(--primary-light);
}

.dark-mode .toolbar-select {
    background: var(--dark-card);
    color: var(--dark-text);
}

.color-input {
    width: 34px;
    height: 34px;
    padding: 3px;
    border: 1px solid var(--grid-border);
    border-radius: var(--border-radius-sm);
    background: var(--light-card);
    cursor: pointer;
    transition: border-color var(--transition-fast), transform var(--transition-fast);
}

.color-input:hover {
    border-color: var(--primary-color);
    transform: scale(1.05) translateZ(0);
}

.dark-mode .color-input {
    background: var(--dark-card);
    border-color: var(--grid-border);
}

/* Formula Bar - Enhanced */
.formula-bar {
    display: flex;
    align-items: center;
    padding: 8px 12px;
    background: var(--formula-bg);
    backdrop-filter: var(--glass-blur);
    border-bottom: 1px solid var(--grid-border);
    gap: 8px;
}

.cell-address {
    font-weight: 700;
    font-size: 13px;
    padding: 6px 12px;
    min-width: 55px;
    text-align: center;
    background: var(--light-card);
    border: 1px solid var(--grid-border);
    border-radius: var(--border-radius-sm);
    color: var(--primary-color);
    font-family: 'JetBrains Mono', 'Consolas', monospace;
}

.dark-mode .cell-address {
    background: var(--dark-card);
}

#formula-input {
    flex: 1;
    padding: 8px 12px;
    border: 2px solid var(--grid-border);
    border-radius: var(--border-radius-sm);
    font-family: 'JetBrains Mono', 'Consolas', 'Courier New', monospace;
    font-size: 13px;
    background: var(--light-card);
    color: var(--light-text);
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

#formula-input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px var(--primary-light);
}

.dark-mode #formula-input {
    background: var(--dark-card);
    color: var(--dark-text);
}

.formula-help-btn {
    background: transparent;
    border: none;
    color: #64748b;
    font-size: 18px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 34px;
    height: 34px;
    border-radius: 50%;
    transition: all var(--transition-fast);
}

.formula-help-btn:hover {
    color: var(--primary-color);
    background: var(--primary-light);
    transform: scale(1.1) translateZ(0);
}

.formula-hint {
    margin: 0;
    font-size: 11px;
    color: #64748b;
    padding: 6px 12px;
    background: rgba(59, 130, 246, 0.04);
    border-bottom: 1px solid var(--grid-border);
}

.formula-hint strong {
    color: var(--primary-color);
}

.formula-hint code {
    background: var(--primary-light);
    padding: 2px 6px;
    border-radius: 4px;
    font-family: 'JetBrains Mono', 'Consolas', monospace;
    font-size: 11px;
}

.formula-hint span {
    display: block;
    margin-top: 2px;
    font-size: 11px;
}

.dark-mode .formula-hint {
    color: #94a3b8;
    background: rgba(139, 92, 246, 0.06);
}

.dark-mode .formula-hint code {
    background: rgba(139, 92, 246, 0.15);
}

/* Formula Function List - Enhanced */
.formula-function-list {
    list-style: none;
    padding: 0;
    margin: 15px 0 0;
    max-height: 340px;
    overflow-y: auto;
    scrollbar-width: thin;
    scrollbar-color: var(--grid-border) transparent;
}

.formula-function-list::-webkit-scrollbar {
    width: 6px;
}

.formula-function-list::-webkit-scrollbar-track {
    background: transparent;
}

.formula-function-list::-webkit-scrollbar-thumb {
    background: var(--grid-border);
    border-radius: 3px;
}

.formula-function-list li {
    margin-bottom: 12px;
    border-left: 3px solid transparent;
    padding: 10px 12px;
    border-radius: 0 var(--border-radius-sm) var(--border-radius-sm) 0;
    background: rgba(59, 130, 246, 0.03);
    transition: all var(--transition-fast);
}

.formula-function-list li:hover {
    background: var(--primary-light);
    border-left-color: var(--primary-color);
    transform: translateX(4px) translateZ(0);
}

.formula-function-list h3 {
    margin: 0 0 6px;
    font-size: 14px;
    color: var(--primary-color);
    font-weight: 600;
}

.formula-function-list code {
    background: var(--primary-light);
    padding: 3px 8px;
    border-radius: 4px;
    display: inline-block;
    margin-bottom: 6px;
    font-size: 12px;
    font-family: 'JetBrains Mono', 'Consolas', monospace;
}

.formula-function-list p {
    margin: 0;
    font-size: 13px;
    color: #475569;
    line-height: 1.5;
}

.dark-mode .formula-function-list li {
    background: rgba(139, 92, 246, 0.05);
}

.dark-mode .formula-function-list li:hover {
    background: rgba(139, 92, 246, 0.12);
    border-left-color: var(--secondary-color);
}

.dark-mode .formula-function-list p {
    color: #cbd5e1;
}

.formula-function-list li.custom-function-entry {
    border-left-color: var(--secondary-color);
    background: rgba(139, 92, 246, 0.05);
}

.formula-search {
    width: 100%;
    padding: 10px 14px;
    border: 2px solid var(--grid-border);
    border-radius: var(--border-radius);
    margin-top: 12px;
    font-size: 14px;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.formula-search:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px var(--primary-light);
}

.function-help {
    max-width: 560px;
}

.custom-function-modal {
    max-width: 680px;
}

/* Custom Function Form - Enhanced */
.custom-function-form .form-group {
    display: flex;
    flex-direction: column;
    margin-bottom: 14px;
    gap: 6px;
}

.custom-function-form label {
    font-weight: 600;
    font-size: 13px;
    color: var(--light-text);
}

.dark-mode .custom-function-form label {
    color: var(--dark-text);
}

.custom-function-form input,
.custom-function-form textarea {
    border: 2px solid var(--grid-border);
    border-radius: var(--border-radius-sm);
    padding: 10px 12px;
    font-family: 'JetBrains Mono', 'Consolas', monospace;
    font-size: 13px;
    background: var(--light-card);
    color: var(--light-text);
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.custom-function-form input:focus,
.custom-function-form textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px var(--primary-light);
}

.dark-mode .custom-function-form input,
.dark-mode .custom-function-form textarea {
    background: var(--dark-card);
    color: var(--dark-text);
}

.custom-func-actions {
    display: flex;
    gap: 10px;
    margin-bottom: 18px;
    flex-wrap: wrap;
}

.custom-function-list {
    list-style: none;
    margin: 16px 0 0;
    padding: 0;
    max-height: 280px;
    overflow-y: auto;
    scrollbar-width: thin;
}

.custom-function-list li {
    border: 1px solid var(--grid-border);
    border-radius: var(--border-radius);
    padding: 14px;
    margin-bottom: 12px;
    background: rgba(148, 163, 184, 0.06);
    transition: all var(--transition-fast);
}

.custom-function-list li:hover {
    background: var(--primary-light);
    border-color: var(--primary-color);
    transform: translateY(-2px) translateZ(0);
    box-shadow: var(--box-shadow);
}

.dark-mode .custom-function-list li {
    background: rgba(71, 85, 105, 0.2);
}

.dark-mode .custom-function-list li:hover {
    background: rgba(139, 92, 246, 0.15);
    border-color: var(--secondary-color);
}

.custom-function-list h3 {
    margin: 0 0 6px;
    font-size: 14px;
    color: var(--primary-color);
    font-weight: 600;
}

.custom-function-list code {
    display: block;
    margin-bottom: 8px;
    background: var(--primary-light);
    padding: 6px 10px;
    border-radius: var(--border-radius-sm);
    font-size: 12px;
    font-family: 'JetBrains Mono', 'Consolas', monospace;
}

.custom-function-list p {
    margin: 0 0 10px;
    font-size: 13px;
    color: #475569;
    line-height: 1.5;
}

.dark-mode .custom-function-list p {
    color: #94a3b8;
}

.custom-function-list .custom-func-actions {
    justify-content: flex-end;
    margin-bottom: 0;
}

/* Button Utility Styles - Enhanced */
.custom-function-modal .primary-btn,
.custom-function-modal .secondary-btn,
.custom-function-modal .danger-btn {
    border: none;
    border-radius: var(--border-radius-sm);
    padding: 10px 18px;
    cursor: pointer;
    font-weight: 600;
    font-size: 13px;
    width: auto;
    margin-top: 0;
    transition: all var(--transition-fast);
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.custom-function-modal .primary-btn {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-hover));
    color: #fff;
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
}

.custom-function-modal .secondary-btn {
    background: var(--primary-light);
    color: var(--primary-color);
}

.custom-function-modal .danger-btn {
    background: rgba(239, 68, 68, 0.12);
    color: #dc2626;
}

.custom-function-modal .primary-btn:hover {
    transform: translateY(-2px) translateZ(0);
    box-shadow: 0 6px 16px rgba(59, 130, 246, 0.4);
}

.custom-function-modal .secondary-btn:hover {
    background: rgba(59, 130, 246, 0.2);
    transform: translateY(-1px) translateZ(0);
}

.custom-function-modal .danger-btn:hover {
    background: rgba(239, 68, 68, 0.2);
    transform: translateY(-1px) translateZ(0);
}

.dark-mode .custom-function-modal .secondary-btn {
    background: rgba(96, 165, 250, 0.15);
    color: #93c5fd;
}

.dark-mode .custom-function-modal .danger-btn {
    background: rgba(239, 68, 68, 0.2);
    color: #fca5a5;
}

/* Spreadsheet Grid */
#spreadsheet {
    flex: 1;
    overflow: hidden;
}

/* Handsontable Custom Styles - GPU Optimized */
.handsontable .htCore th {
    background: var(--header-bg);
    color: var(--light-text);
    font-weight: 600;
    font-size: 12px;
    border-color: var(--grid-border);
    /* GPU acceleration */
    transform: translateZ(0);
}

.dark-mode .handsontable .htCore th {
    color: var(--dark-text);
}

.handsontable .htCore td {
    border-color: var(--grid-border);
    color: var(--light-text);
    font-size: var(--grid-font-size, 13px);
    padding: 4px 8px;
    transition: background-color 60ms linear;
    /* GPU layer for cells */
    transform: translateZ(0);
    will-change: background-color;
}

.dark-mode .handsontable .htCore td {
    color: var(--dark-text);
}

.handsontable .htCore td.current {
    background: var(--cell-selected);
    box-shadow: inset 0 0 0 2px var(--primary-color);
}

.handsontable .htCore td.area {
    background: var(--cell-highlight);
}

/* Awards Highlight Cells - Enhanced */
.handsontable .htCore td.champion-cell {
    background: linear-gradient(135deg, #fef3c7, #fde047);
    font-weight: 700;
    color: #92400e;
    text-shadow: 0 1px 0 rgba(255, 255, 255, 0.5);
    animation: championPulse 2s infinite;
}

@keyframes championPulse {
    0%, 100% { box-shadow: inset 0 0 0 2px rgba(245, 158, 11, 0.3); }
    50% { box-shadow: inset 0 0 0 2px rgba(245, 158, 11, 0.6); }
}

.handsontable .htCore td.runnerup-cell {
    background: linear-gradient(135deg, #f1f5f9, #cbd5e1);
    font-weight: 600;
    color: #475569;
}

.handsontable .htCore td.third-cell {
    background: linear-gradient(135deg, #fed7aa, #fdba74);
    font-weight: 600;
    color: #9a3412;
}

/* Sheet Tabs - Enhanced */
.tab-container {
    display: flex;
    border-top: 1px solid var(--grid-border);
    background: var(--toolbar-bg);
    backdrop-filter: var(--glass-blur);
    padding: 0 12px;
}

.sheet-tabs {
    display: flex;
    overflow-x: auto;
    scrollbar-width: thin;
    gap: 2px;
}

.sheet-tabs::-webkit-scrollbar {
    height: 4px;
}

.sheet-tabs::-webkit-scrollbar-track {
    background: transparent;
}

.sheet-tabs::-webkit-scrollbar-thumb {
    background: var(--grid-border);
    border-radius: 2px;
}

.sheet-tab {
    padding: 10px 18px;
    border: none;
    background: transparent;
    cursor: pointer;
    color: var(--light-text);
    white-space: nowrap;
    font-size: 13px;
    font-weight: 500;
    border-radius: var(--border-radius-sm) var(--border-radius-sm) 0 0;
    transition: all var(--transition-fast);
    position: relative;
}

.sheet-tab::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: all var(--transition-fast);
    transform: translateX(-50%);
}

.sheet-tab:hover {
    background: var(--primary-light);
    color: var(--primary-color);
}

.sheet-tab:hover::after {
    width: 60%;
}

.dark-mode .sheet-tab {
    color: var(--dark-text);
}

.sheet-tab.active {
    background: var(--light-card);
    font-weight: 600;
    color: var(--primary-color);
    box-shadow: 0 -2px 8px rgba(0, 0, 0, 0.05);
}

.sheet-tab.active::after {
    width: 100%;
}

.dark-mode .sheet-tab.active {
    background: var(--dark-card);
}

.add-sheet-btn {
    padding: 10px 14px;
    border: none;
    background: transparent;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--primary-color);
    border-radius: var(--border-radius-sm);
    transition: all var(--transition-fast);
}

.add-sheet-btn:hover {
    background: var(--primary-light);
    transform: scale(1.1) translateZ(0);
}

/* Modal Styles - Enhanced */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    z-index: 200;
    align-items: center;
    justify-content: center;
}

.modal-content {
    background: var(--light-card);
    padding: 24px;
    border-radius: var(--border-radius-lg);
    max-width: 520px;
    width: 92%;
    position: relative;
    box-shadow: var(--box-shadow-lg), 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    animation: modalSlideIn 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
    border: 1px solid var(--grid-border);
}

@keyframes modalSlideIn {
    from {
        opacity: 0;
        transform: scale(0.95) translateY(20px);
    }
    to {
        opacity: 1;
        transform: scale(1) translateY(0);
    }
}

.dark-mode .modal-content {
    background: var(--dark-card);
}

.close-modal {
    position: absolute;
    top: 14px;
    right: 18px;
    font-size: 24px;
    cursor: pointer;
    color: #64748b;
    width: 32px;
    height: 32px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: all var(--transition-fast);
}

.close-modal:hover {
    color: var(--danger-color);
    background: rgba(239, 68, 68, 0.1);
}

.dark-mode .close-modal {
    color: #94a3b8;
}

.modal h2 {
    margin-bottom: 20px;
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    font-size: 20px;
    font-weight: 700;
}

.form-group {
    margin-bottom: 16px;
}

.form-group label {
    display: block;
    margin-bottom: 6px;
    font-weight: 600;
    font-size: 13px;
    color: var(--light-text);
}

.dark-mode .form-group label {
    color: var(--dark-text);
}

.form-group input[type="text"],
.form-group select {
    width: 100%;
    padding: 10px 14px;
    border: 2px solid var(--grid-border);
    border-radius: var(--border-radius-sm);
    background: var(--light-card);
    color: var(--light-text);
    font-size: 14px;
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.form-group input[type="text"]:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px var(--primary-light);
}

.dark-mode .form-group input[type="text"],
.dark-mode .form-group select {
    background: var(--dark-bg);
    color: var(--dark-text);
}

.primary-btn {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-hover));
    color: white;
    border: none;
    padding: 12px 20px;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-weight: 600;
    font-size: 14px;
    width: 100%;
    margin-top: 12px;
    transition: all var(--transition);
    box-shadow: 0 4px 14px rgba(59, 130, 246, 0.35);
}

.primary-btn:hover {
    transform: translateY(-2px) translateZ(0);
    box-shadow: 0 6px 20px rgba(59, 130, 246, 0.45);
}

.primary-btn:active {
    transform: translateY(0);
}

/* Awards Preview - Enhanced */
.awards-preview {
    margin: 18px 0;
    padding: 16px;
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.08), rgba(139, 92, 246, 0.08));
    border-radius: var(--border-radius);
    border: 1px solid var(--grid-border);
}

.awards-preview h3 {
    margin-bottom: 14px;
    font-size: 14px;
    color: var(--primary-color);
    font-weight: 600;
}

.award-item {
    display: flex;
    align-items: center;
    margin-bottom: 10px;
    padding: 8px 10px;
    background: var(--light-card);
    border-radius: var(--border-radius-sm);
    transition: transform var(--transition-fast);
}

.award-item:hover {
    transform: translateX(4px) translateZ(0);
}

.dark-mode .award-item {
    background: var(--dark-card);
}

.award-icon {
    display: inline-flex;
    width: 36px;
    height: 36px;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    margin-right: 12px;
    color: white;
    font-size: 16px;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.15);
}

.gold {
    background: linear-gradient(135deg, #fcd34d, #f59e0b);
    box-shadow: 0 4px 12px rgba(245, 158, 11, 0.4);
}

.silver {
    background: linear-gradient(135deg, #e2e8f0, #94a3b8);
    box-shadow: 0 4px 12px rgba(148, 163, 184, 0.4);
}

.bronze {
    background: linear-gradient(135deg, #fdba74, #ea580c);
    box-shadow: 0 4px 12px rgba(234, 88, 12, 0.4);
}

/* Chart Container - Enhanced */
.chart-container {
    position: fixed;
    bottom: 24px;
    right: 24px;
    width: 420px;
    height: 320px;
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--box-shadow-lg);
    border: 1px solid var(--glass-border);
    z-index: 50;
    padding: 16px;
    display: flex;
    flex-direction: column;
    animation: chartSlideIn 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
}

@keyframes chartSlideIn {
    from {
        opacity: 0;
        transform: translateY(20px) scale(0.95);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

.dark-mode .chart-container {
    background: var(--glass-bg);
}

.chart-container.hidden {
    display: none;
}

.chart-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
}

.chart-header h3 {
    background: linear-gradient(135deg, var(--primary-color), var(--secondary-color));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    font-size: 16px;
    font-weight: 600;
}

.close-chart-btn {
    background: transparent;
    border: none;
    font-size: 20px;
    cursor: pointer;
    color: #64748b;
    width: 28px;
    height: 28px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition-fast);
}

.close-chart-btn:hover {
    color: var(--danger-color);
    background: rgba(239, 68, 68, 0.1);
}

.dark-mode .close-chart-btn {
    color: #94a3b8;
}

/* Footer styles - Enhanced */
.footer {
    margin-top: 40px;
    padding: 24px 0;
    text-align: center;
    border-top: 1px solid var(--grid-border);
    background: var(--glass-bg);
    backdrop-filter: var(--glass-blur);
    transition: all var(--transition);
}

.dark-mode .footer {
    border-top-color: var(--grid-border);
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

.footer-links {
    line-height: 1.8;
    color: #64748b;
    font-size: 14px;
}

.dark-mode .footer-links {
    color: #94a3b8;
}

.footer a {
    color: var(--primary-color);
    text-decoration: none;
    transition: all var(--transition-fast);
    font-weight: 500;
}

.footer a:hover {
    color: var(--secondary-color);
    text-decoration: underline;
}

/* Responsive Design - Enhanced */
@media (max-width: 768px) {
    .toolbar {
        padding: 8px;
        gap: 6px;
    }
    
    .toolbar-group {
        padding-right: 8px;
    }
    
    .toolbar-btn {
        width: 32px;
        height: 32px;
    }
    
    .chart-container {
        width: 85%;
        left: 7.5%;
        right: 7.5%;
        bottom: 16px;
    }
    
    .page-title h1 {
        font-size: 26px;
    }
    
    .page-title p {
        font-size: 14px;
    }
    
    .spreadsheet-container {
        height: 65vh;
        min-height: 400px;
    }
    
    .formula-bar {
        flex-wrap: wrap;
        gap: 8px;
    }
    
    .cell-address {
        min-width: 50px;
    }
}

@media (max-width: 480px) {
    .toolbar-group:not(.file-operations):not(.special) {
        display: none;
    }
    
    .formula-bar {
        flex-direction: column;
        align-items: stretch;
        padding: 8px;
    }
    
    .cell-address {
        width: auto;
        display: inline-flex;
        align-self: flex-start;
    }
    
    #formula-input {
        width: 100%;
    }
    
    .header-container {
        padding: 12px 16px;
    }
    
    .site-title {
        font-size: 18px;
    }
    
    .logo {
        height: 32px;
    }
}

/* Panning cursor when Space+drag */
.spreadsheet-container.panning, 
.spreadsheet-container.panning * {
    cursor: grabbing !important;
}

/* Subtle row hover - GPU optimized */
.handsontable .htCore tbody tr:hover td {
    background: var(--cell-highlight);
}

/* Header hover highlight */
.handsontable .htCore thead th.hover-header,
.handsontable .htCore tbody th.hover-header {
    background: var(--header-bg);
    box-shadow: inset 0 -2px 0 var(--primary-color);
    font-weight: 700;
}

/* Zoomable font size */
.handsontable .htCore td,
.handsontable .htCore th {
    font-size: var(--grid-font-size, 13px);
}

/* Selection highlight enhancement */
.handsontable .htCore td.current.highlight {
    box-shadow: inset 0 0 0 2px var(--primary-color), 0 0 12px var(--primary-glow);
}

/* Smooth scrolling for spreadsheet */
.handsontable .wtHolder {
    scrollbar-width: thin;
    scrollbar-color: var(--grid-border) transparent;
}

.handsontable .wtHolder::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

.handsontable .wtHolder::-webkit-scrollbar-track {
    background: transparent;
}

.handsontable .wtHolder::-webkit-scrollbar-thumb {
    background: var(--grid-border);
    border-radius: 4px;
}

.handsontable .wtHolder::-webkit-scrollbar-thumb:hover {
    background: var(--primary-color);
}

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