/* ========================================
   Design System & CSS Variables
   ======================================== */
:root {
    /* Color Palette */
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --secondary-gradient: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --success-gradient: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
    --warning-gradient: linear-gradient(135deg, #fa709a 0%, #fee140 100%);

    --primary-color: #667eea;
    --secondary-color: #764ba2;
    --accent-color: #f093fb;
    --success-color: #4facfe;
    --warning-color: #fa709a;
    --danger-color: #f5576c;

    /* Neutral Colors */
    --bg-primary: #0f0f23;
    --bg-secondary: #1a1a2e;
    --bg-tertiary: #252541;
    --bg-card: #1e1e3f;
    --bg-hover: #2a2a4a;

    --text-primary: #ffffff;
    --text-secondary: #b4b4d4;
    --text-muted: #7676a0;
    --text-inverse: #0f0f23;

    --border-color: rgba(255, 255, 255, 0.08);
    --border-hover: rgba(255, 255, 255, 0.15);

    /* Shadows */
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 40px rgba(102, 126, 234, 0.3);

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 0.75rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;

    /* Border Radius */
    --radius-sm: 6px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-full: 9999px;

    /* Typography */
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-size-xs: 0.75rem;
    --font-size-sm: 0.875rem;
    --font-size-base: 1rem;
    --font-size-lg: 1.125rem;
    --font-size-xl: 1.25rem;
    --font-size-2xl: 1.5rem;
    --font-size-3xl: 2rem;

    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* ========================================
   Global Styles
   ======================================== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: var(--font-family);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ========================================
   App Container
   ======================================== */
.app-container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* ========================================
   Header
   ======================================== */
.app-header {
    background: var(--bg-card);
    border-bottom: 1px solid var(--border-color);
    padding: var(--spacing-lg) var(--spacing-xl);
    display: flex;
    justify-content: space-between;
    align-items: center;
    backdrop-filter: blur(20px);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow-md);
}

.header-left {
    display: flex;
    align-items: center;
    gap: var(--spacing-lg);
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.logo svg {
    filter: drop-shadow(0 4px 12px rgba(102, 126, 234, 0.4));
    animation: logoFloat 3s ease-in-out infinite;
}

@keyframes logoFloat {

    0%,
    100% {
        transform: translateY(0);
    }

    50% {
        transform: translateY(-4px);
    }
}

.logo-text h1 {
    font-size: var(--font-size-xl);
    font-weight: 700;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.02em;
}

.logo-text p {
    font-size: var(--font-size-xs);
    color: var(--text-muted);
    margin-top: 2px;
}

/* ========================================
   Buttons
   ======================================== */
.btn {
    padding: var(--spacing-sm) var(--spacing-lg);
    border: none;
    border-radius: var(--radius-md);
    font-size: var(--font-size-sm);
    font-weight: 600;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
    font-family: var(--font-family);
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.2);
    transform: translate(-50%, -50%);
    transition: width var(--transition-slow), height var(--transition-slow);
}

.btn:hover::before {
    width: 300px;
    height: 300px;
}

.btn-primary {
    background: var(--primary-gradient);
    color: white;
    box-shadow: 0 4px 16px rgba(102, 126, 234, 0.4);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(102, 126, 234, 0.5);
}

.btn-secondary {
    background: var(--bg-tertiary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: var(--bg-hover);
    border-color: var(--border-hover);
}

/* ========================================
   Main Content Layout
   ======================================== */
.main-content {
    display: grid;
    grid-template-columns: 280px 1fr;
    flex: 1;
    gap: var(--spacing-xl);
    padding: var(--spacing-xl);
    max-width: 1800px;
    margin: 0 auto;
    width: 100%;
}

/* ========================================
   Sidebar
   ======================================== */
.sidebar {
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    height: fit-content;
    max-height: calc(100vh - 140px);
    overflow-y: auto;
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-md);
    position: sticky;
    top: 100px;
}

.sidebar-header h3 {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.search-box {
    position: relative;
    margin-bottom: var(--spacing-lg);
}

.search-box svg {
    position: absolute;
    left: var(--spacing-md);
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
}

.search-box input {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md) var(--spacing-sm) 2.5rem;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: var(--font-size-sm);
    transition: all var(--transition-base);
    font-family: var(--font-family);
}

.search-box input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.search-box input::placeholder {
    color: var(--text-muted);
}

/* Class Select & Inputs */
.class-select {
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: var(--font-size-sm);
    transition: all var(--transition-base);
    font-family: var(--font-family);
}

.class-select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

/* Filter Tabs */
.filter-tabs {
    display: flex;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-lg);
    background: var(--bg-tertiary);
    padding: 4px;
    border-radius: var(--radius-md);
}

.filter-tab {
    flex: 1;
    padding: var(--spacing-xs) var(--spacing-sm);
    background: transparent;
    border: none;
    border-radius: var(--radius-sm);
    color: var(--text-muted);
    font-size: var(--font-size-xs);
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition-base);
    font-family: var(--font-family);
}

.filter-tab.active {
    background: var(--primary-gradient);
    color: white;
    box-shadow: var(--shadow-sm);
}

.filter-tab:hover:not(.active) {
    color: var(--text-primary);
    background: var(--bg-hover);
}

/* Student List */
.student-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-sm);
}

.student-item {
    padding: var(--spacing-md);
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    cursor: pointer;
    transition: all var(--transition-base);
}

.student-item:hover {
    background: var(--bg-hover);
    border-color: var(--border-hover);
    transform: translateX(4px);
}

.student-item.active {`r`n    background: #e3f2fd;`r`n    border-color: #90caf9;`r`n    box-shadow: 0 4px 12px rgba(144, 202, 249, 0.3);`r`n}

.student-item-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-xs);
}

.student-item-name {
    font-weight: 600;
    font-size: var(--font-size-base);
}

.student-item-rank {
    font-size: var(--font-size-lg);
    font-weight: 700;
    color: var(--accent-color);
}

.student-item.active .student-item-rank {`r`n    color: #1976d2;`r`n}

.student-item-id {
    font-size: var(--font-size-xs);
    color: var(--text-muted);
}

.student-item.active .student-item-id {`r`n    color: #1565c0;`r`n}

.student-item-score {
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    margin-top: var(--spacing-xs);
}

.student-item.active .student-item-score {`r`n    color: #0d47a1;`r`n}

/* ========================================
   Main Panel
   ======================================== */
.main-panel {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
}

/* Student Info Card */
.student-info-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    display: grid;
    grid-template-columns: auto 1fr auto;
    gap: var(--spacing-xl);
    align-items: center;
    box-shadow: var(--shadow-md);
    position: relative;
    overflow: hidden;
}

.student-info-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: var(--primary-gradient);
}

.student-avatar {
    width: 80px;
    height: 80px;
    border-radius: var(--radius-full);
    background: var(--primary-gradient);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: var(--font-size-2xl);
    font-weight: 700;
    color: white;
    box-shadow: var(--shadow-glow);
    animation: avatarPulse 2s ease-in-out infinite;
}

@keyframes avatarPulse {

    0%,
    100% {
        transform: scale(1);
    }

    50% {
        transform: scale(1.05);
    }
}

.student-details h2 {
    font-size: var(--font-size-2xl);
    margin-bottom: var(--spacing-xs);
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.student-meta {
    display: flex;
    gap: var(--spacing-lg);
    color: var(--text-secondary);
    font-size: var(--font-size-sm);
}

.meta-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.student-stats {
    display: flex;
    gap: var(--spacing-2xl);
}

.stat-item {
    text-align: right;
}

.stat-label {
    display: block;
    font-size: var(--font-size-sm);
    color: var(--text-muted);
    margin-bottom: var(--spacing-xs);
}

.stat-value {
    display: block;
    font-size: var(--font-size-3xl);
    font-weight: 700;
    background: var(--secondary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* Subject Selection Card */
.subject-selection-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-md);
}

.card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-lg);
}

.card-header h3 {
    font-size: var(--font-size-lg);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.card-header h3 svg {
    color: var(--primary-color);
}

.subtitle {
    font-size: var(--font-size-sm);
    color: var(--text-muted);
    font-weight: 400;
    margin-left: var(--spacing-sm);
}

.subject-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(80px, 1fr));
    gap: var(--spacing-sm);
}

.subject-checkbox {
    position: relative;
}

.subject-checkbox input[type="checkbox"] {
    position: absolute;
    opacity: 0;
    cursor: pointer;
}

.subject-label {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: var(--spacing-sm) var(--spacing-xs);
    background: var(--bg-tertiary);
    border: 2px solid var(--border-color);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all var(--transition-base);
}

.subject-checkbox input:checked+.subject-label {
    background: var(--primary-gradient);
    border-color: var(--primary-color);
    box-shadow: 0 4px 16px rgba(102, 126, 234, 0.4);
    transform: translateY(-2px);
}

.subject-name {
    font-weight: 600;
    font-size: var(--font-size-sm);
    margin-bottom: 0;
}

.subject-checkbox input:checked+.subject-label .subject-name {
    color: white;
}

.subject-score {
    font-size: 10px;
    color: var(--text-muted);
}

.subject-checkbox input:checked+.subject-label .subject-score {
    color: rgba(255, 255, 255, 0.9);
}

/* ========================================
   Charts
   ======================================== */
.charts-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--spacing-xl);
}

.chart-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-md);
}

.chart-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-lg);
}

.chart-header h3 {
    font-size: var(--font-size-lg);
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
}

.chart-header svg {
    color: var(--primary-color);
}

.chart-legend {
    display: flex;
    gap: var(--spacing-lg);
}

.legend-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
}

.legend-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
}

canvas {
    max-height: 300px;
}

/* ========================================
   Table
   ======================================== */
.table-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-md);
}

.table-container {
    overflow-x: auto;
    margin-top: var(--spacing-lg);
}

table {
    width: 100%;
    border-collapse: collapse;
}

thead tr {
    background: var(--bg-tertiary);
}

th {
    padding: var(--spacing-md);
    text-align: left;
    font-weight: 600;
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
    border-bottom: 2px solid var(--border-color);
}

tbody tr {
    border-bottom: 1px solid var(--border-color);
    transition: all var(--transition-base);
}

tbody tr:hover {
    background: var(--bg-tertiary);
}

td {
    padding: var(--spacing-md);
    font-size: var(--font-size-sm);
}

.exam-name {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.exam-indicator {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--primary-gradient);
}

.table-note {
    margin-top: var(--spacing-md);
    font-size: var(--font-size-xs);
    color: var(--text-muted);
    font-style: italic;
}

/* ========================================
   Modal
   ======================================== */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(10px);
    z-index: 1000;
    align-items: center;
    justify-content: center;
    animation: modalFadeIn var(--transition-base);
}

.modal.active {
    display: flex;
}

@keyframes modalFadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

.modal-content {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    max-width: 600px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
    box-shadow: var(--shadow-lg);
    animation: modalSlideUp var(--transition-slow);
}

@keyframes modalSlideUp {
    from {
        transform: translateY(50px);
        opacity: 0;
    }

    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.modal-header {
    padding: var(--spacing-xl);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-header h2 {
    font-size: var(--font-size-xl);
}

.modal-close {
    background: none;
    border: none;
    font-size: var(--font-size-3xl);
    color: var(--text-muted);
    cursor: pointer;
    line-height: 1;
    transition: all var(--transition-base);
}

.modal-close:hover {
    color: var(--text-primary);
    transform: rotate(90deg);
}

.modal-body {
    padding: var(--spacing-xl);
}

.upload-area {
    border: 2px dashed var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-2xl);
    text-align: center;
    cursor: pointer;
    transition: all var(--transition-base);
    margin-bottom: var(--spacing-xl);
}

.upload-area:hover {
    border-color: var(--primary-color);
    background: var(--bg-tertiary);
}

.upload-area svg {
    color: var(--primary-color);
    margin-bottom: var(--spacing-md);
}

.upload-area h3 {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-sm);
}

.upload-area p {
    color: var(--text-muted);
    font-size: var(--font-size-sm);
}

.upload-instructions h4 {
    font-size: var(--font-size-base);
    margin-bottom: var(--spacing-md);
}

.upload-instructions ul {
    list-style: none;
    padding: 0;
}

.upload-instructions li {
    padding: var(--spacing-sm) 0;
    padding-left: var(--spacing-lg);
    border-bottom: 2px solid var(--border-color);
}

tbody tr {
    border-bottom: 1px solid var(--border-color);
    transition: all var(--transition-base);
}

tbody tr:hover {
    background: var(--bg-tertiary);
}

td {
    padding: var(--spacing-md);
    font-size: var(--font-size-sm);
}

.exam-name {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.exam-indicator {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--primary-gradient);
}

.table-note {
    margin-top: var(--spacing-md);
    font-size: var(--font-size-xs);
    color: var(--text-muted);
    font-style: italic;
}

/* ========================================
   Modal
   ======================================== */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.8);
    backdrop-filter: blur(10px);
    z-index: 1000;
    align-items: center;
    justify-content: center;
    animation: modalFadeIn var(--transition-base);
}

.modal.active {
    display: flex;
}

@keyframes modalFadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

.modal-content {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    max-width: 600px;
    width: 90%;
    max-height: 80vh;
    overflow-y: auto;
    box-shadow: var(--shadow-lg);
    animation: modalSlideUp var(--transition-slow);
}

@keyframes modalSlideUp {
    from {
        transform: translateY(50px);
        opacity: 0;
    }

    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.modal-header {
    padding: var(--spacing-xl);
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-header h2 {
    font-size: var(--font-size-xl);
}

.modal-close {
    background: none;
    border: none;
    font-size: var(--font-size-3xl);
    color: var(--text-muted);
    cursor: pointer;
    line-height: 1;
    transition: all var(--transition-base);
}

.modal-close:hover {
    color: var(--text-primary);
    transform: rotate(90deg);
}

.modal-body {
    padding: var(--spacing-xl);
}

.upload-area {
    border: 2px dashed var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-2xl);
    text-align: center;
    cursor: pointer;
    transition: all var(--transition-base);
    margin-bottom: var(--spacing-xl);
}

.upload-area:hover {
    border-color: var(--primary-color);
    background: var(--bg-tertiary);
}

.upload-area svg {
    color: var(--primary-color);
    margin-bottom: var(--spacing-md);
}

.upload-area h3 {
    font-size: var(--font-size-lg);
    margin-bottom: var(--spacing-sm);
}

.upload-area p {
    color: var(--text-muted);
    font-size: var(--font-size-sm);
}

.upload-instructions h4 {
    font-size: var(--font-size-base);
    margin-bottom: var(--spacing-md);
}

.upload-instructions ul {
    list-style: none;
    padding: 0;
}

.upload-instructions li {
    padding: var(--spacing-sm) 0;
    padding-left: var(--spacing-lg);
    position: relative;
    font-size: var(--font-size-sm);
    color: var(--text-secondary);
}

.upload-instructions li::before {
    content: '�;
 position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: 700;
}

/* ========================================
   Scrollbar Styling
   ======================================== */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-tertiary);
}

::-webkit-scrollbar-thumb {
    background: var(--primary-gradient);
    border-radius: var(--radius-full);
}

::-webkit-scrollbar-thumb:hover {
    background: var(--secondary-gradient);
}

/* ========================================
   Responsive Design
   ======================================== */
@media (max-width: 1200px) {
    .main-content {
        grid-template-columns: 250px 1fr;
    }

    .charts-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 968px) {
    .main-content {
        grid-template-columns: 1fr;
        padding: var(--spacing-md);
        gap: var(--spacing-lg);
    }

    .sidebar {
        position: static;
        max-height: none;
        margin-bottom: var(--spacing-lg);
    }

    /* Limit student list height on mobile */
    .student-list {
        max-height: 300px;
        overflow-y: auto;
        border: 1px solid var(--border-color);
        border-radius: var(--radius-md);
    }

    .student-info-card {
        grid-template-columns: 1fr;
        text-align: center;
        padding: var(--spacing-lg);
        gap: var(--spacing-lg);
    }

    .student-avatar {
        margin: 0 auto;
    }

    .student-meta {
        justify-content: center;
    }

    .student-stats {
        justify-content: center;
        gap: var(--spacing-xl);
    }
}

@media (max-width: 640px) {
    :root {
        --spacing-xl: 1.5rem;
        --spacing-2xl: 2rem;
    }

    .app-header {
        flex-direction: column;
        gap: var(--spacing-md);
        padding: var(--spacing-md);
    }

    .header-left,
    .header-right {
        width: 100%;
        justify-content: center;
        flex-wrap: wrap;
    }

    .logo-text h1 {
        font-size: var(--font-size-lg);
    }

    .btn {
        padding: var(--spacing-xs) var(--spacing-md);
        font-size: var(--font-size-xs);
    }

    .subject-grid {
        grid-template-columns: repeat(auto-fill, minmax(80px, 1fr));
        gap: var(--spacing-sm);
    }

    .subject-label {
        padding: var(--spacing-md) var(--spacing-sm);
    }

    .student-stats {
        flex-direction: column;
        gap: var(--spacing-lg);
    }

    .stat-value {
        font-size: var(--font-size-2xl);
    }

    .modal-content {
        width: 95%;
        margin: var(--spacing-md);
        max-height: 90vh;
    }

    .modal-header,
    .modal-body {
        padding: var(--spacing-lg);
    }

    canvas {
        max-height: 250px;
    }

    .large-table-container {
        border-radius: 0;
    }
}

/* ========================================
   Grade Filter Styles
   ======================================== */
.grade-filter-container {
    margin-top: var(--spacing-md);
    margin-bottom: var(--spacing-md);
    background: var(--bg-tertiary);
    border-radius: var(--radius-md);
    overflow: hidden;
}

.filter-title {
    padding: 12px 20px;
    font-size: 13px;
    font-weight: 600;
    color: #b4b4d4;
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
}

.grade-filter-option {
    display: block;
    padding: 10px 20px;
    cursor: pointer;
    transition: background 0.2s;
    color: var(--text-secondary);
}

.grade-filter-option:hover {
    background: var(--bg-hover);
}

.grade-filter-option input[type="radio"] {
    margin-right: 8px;
    cursor: pointer;
}

.grade-filter-option input[type="radio"]:checked+span {
    color: var(--primary-color);
    font-weight: 600;
}

.grade-filter-option span {
    font-size: var(--font-size-sm);
}

/* Class Filter */
.class-filter-box {
    margin-top: 12px;
    position: relative;
}

.class-select {
    width: 100%;
    padding: 10px 12px;
    padding-right: 30px;
    background: var(--bg-tertiary);
    border: 1px solid rgba(255, 255, 255, 0.3);
    border-radius: 8px;
    color: var(--text-primary);
    font-size: 14px;

    cursor: pointer;
    transition: all 0.3s ease;
}

.class-select::placeholder {
    color: var(--text-muted);
}

.class-select option {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

.class-select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.1);
}

.select-icon {
    position: absolute;
    right: 12px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-secondary);
    pointer-events: none;
}

/* Large Modal */
.modal-large {
    width: 90%;
    max-width: 1200px;
    height: 85vh;
    display: flex;
    flex-direction: column;
}

.large-table-container {
    flex: 1;
    overflow: auto;
    border-radius: 0 0 16px 16px;
}

#bigRankTable th,
#bigRankTable td {
    padding: 12px 16px;
    text-align: left;
    white-space: nowrap;
}

#bigRankTable th {
    background: var(--bg-secondary);
    font-weight: 600;
    color: var(--text-secondary);
    position: sticky;
    top: 0;
    z-index: 10;
}

#bigRankTable tbody tr:nth-child(even) {
    background: rgba(255, 255, 255, 0.02);
}

#bigRankTable tbody tr:hover {
    background: var(--bg-hover);
}

[data-theme="light"] {
    /* Neutral Colors */
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-tertiary: #f0f2f5;
    --bg-card: #ffffff;
    --bg-hover: #f5f5f7;

    --text-primary: #1a1a2e;
    --text-secondary: #4a4a6a;
    --text-muted: #8a8a9a;
    --text-inverse: #ffffff;

    --border-color: rgba(0, 0, 0, 0.06);
    --border-hover: rgba(0, 0, 0, 0.1);

    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-glow: 0 0 20px rgba(102, 126, 234, 0.1);
}

@media (max-width: 768px) {
    .sidebar {
        max-height: calc(100vh - 200px) !important;
        height: auto !important;
        overflow-y: auto !important;
    }
}

@keyframes spin  {
     from  {
         transform:  rotate(0deg);
         
    }

     to  {
         transform:  rotate(360deg);
         
    }

     
}

  /* Mobile Rank Table Styles */ .expand-cell  {
     text-align:  center;
     padding:  8px  !important;
     
}

 .expand-btn  {
     background:  transparent;
     border:  none;
     cursor:  pointer;
     padding:  4px;
     display:  flex;
     align-items:  center;
     justify-content:  center;
     color:  var(--primary-color);
     transition:  all 0.3s ease;
     
}

 .expand-btn:hover  {
     background:  var(--bg-tertiary);
     border-radius:  4px;
     
}

 .expand-icon  {
     transition:  transform 0.3s ease;
     
}

 .rank-detail-row  {
     background:  var(--bg-tertiary);
     
}

 .detail-cell  {
     padding:  16px  !important;
     
}

 .subject-details  {
     display:  grid;
     grid-template-columns:  repeat(auto-fill,  minmax(120px,  1fr));
     gap:  12px;
     
}

 .subject-detail-item  {
     display:  flex;
     justify-content:  space-between;
     align-items:  center;
     padding:  8px 12px;
     background:  var(--bg-card);
     border-radius:  8px;
     border:  1px solid var(--border-color);
     
}

 .subject-name  {
     font-size:  14px;
     color:  var(--text-secondary);
     font-weight:  500;
     
}

 .subject-score  {
     font-size:  16px;
     color:  var(--primary-color);
     font-weight:  600;
     
}

 @media (max-width: 768px)  {
     .subject-details  {
         grid-template-columns:  repeat(2,  1fr);
         
    }

     
}

  /* Rank Medals */ .rank-medal  {
     display:  inline-block;
     width:  24px;
     height:  24px;
     line-height:  24px;
     text-align:  center;
     border-radius:  50%;
     color:  white;
     font-weight:  bold;
     font-size:  12px;
     
}

 .rank-1  {
     background:  linear-gradient(135deg,  #FFD700,  #FDB931);
     box-shadow:  0 2px 4px rgba(255,  215,  0,  0.3);
     
}

 .rank-2  {
     background:  linear-gradient(135deg,  #E0E0E0,  #BDBDBD);
     box-shadow:  0 2px 4px rgba(189,  189,  189,  0.3);
     
}

 .rank-3  {
     background:  linear-gradient(135deg,  #CD7F32,  #A0522D);
     box-shadow:  0 2px 4px rgba(205,  127,  50,  0.3);
     
}

 /* Mobile Table Optimizations */ @media (max-width: 768px)  {
     .rank-table-row  {
         cursor:  pointer;
         -webkit-tap-highlight-color:  transparent;
         
    }

     .rank-table-row:active  {
         background-color:  var(--bg-tertiary);
         
    }

     .student-name-cell  {
         font-weight:  600;
         
    }

     .rank-detail-row td  {
         padding:  0  !important;
         border:  none  !important;
         
    }

     .subject-details  {
         padding:  12px;
         background:  var(--bg-tertiary);
         border-radius:  0 0 8px 8px;
         margin-bottom:  8px;
         box-shadow:  inset 0 2px 4px rgba(0, 0, 0, 0.05);
         
    }

     
}

  /* Rank Modal Header Controls */ #rankHeaderControls  {
     display:  flex;
     align-items:  center;
     gap:  12px;
     flex-wrap:  wrap;
     
}

 /* Default widths for desktop */ #rankViewType  {
     width:  140px;
     
}

 #rankExamSelect  {
     width:  200px;
     
}

 #rankFilterName  {
     width:  120px;
     
}

 #rankFilterClass  {
     width:  120px;
     
}

 #rankFilterType  {
     width:  100px;
     
}

 /* Mobile Responsive Styles */ @media (max-width: 768px)  {
     #rankHeaderControls  {
         flex-direction:  column;
         align-items:  stretch;
         gap:  10px;
         padding-bottom:  10px;
         
    }

     #rankHeaderControls .class-select,
     #rankHeaderControls input,
     #rankHeaderControls select  {
         width:  100%  !important;
         margin:  0  !important;
         
    }

     #rankAIAnalysisBtn  {
         width:  100%;
         justify-content:  center;
         margin-left:  0  !important;
         display:  flex  !important;

         /* Ensure it's visible if configured */ } }
  /* Rank Header Responsive Styles */ .rank-header-controls  {
             display:  flex;
             align-items:  center;
             gap:  20px;
             flex-wrap:  wrap;
             
        }

         @media (max-width: 768px)  {
             .rank-header-controls  {
                 flex-direction:  column;
                 align-items:  stretch;
                 gap:  12px;
                 padding-bottom:  10px;
                 
            }

             .rank-header-controls h2  {
                 text-align:  center;
                 width:  100%;
                 margin-bottom:  5px;
                 
            }

             .rank-header-controls select,
             .rank-header-controls input  {
                 width:  100%  !important;
                 max-width:  none  !important;
                 margin:  0  !important;
                 
            }

             .rank-header-controls button#rankAIAnalysisBtn  {
                 width:  100%  !important;
                 margin:  0  !important;
                 margin-top:  5px  !important;
                 justify-content:  center;
                 
            }

             
        }

          /* Mobile Table Compact Styles */ @media (max-width: 768px)  {

             #bigRankTable th,
             #bigRankTable td  {
                 padding:  10px 4px  !important;
                 font-size:  13px;
                 
            }

             #bigRankTable th:nth-child(4),
             #bigRankTable td:nth-child(4),
             #bigRankTable th:nth-child(5),
             #bigRankTable td:nth-child(5)  {
                 text-align:  center;
                 padding-left:  2px  !important;
                 padding-right:  2px  !important;
                 
            }

             
        }

          /* Mobile Detail Alignment */ @media (max-width: 768px)  {
             .subject-details  {
                 display:  flex  !important;
                 flex-wrap:  wrap;
                 justify-content:  flex-end  !important;
                 gap:  8px  !important;
                 
            }

             .subject-detail-item  {
                 width:  auto  !important;
                 min-width:  90px;
                 
            }

             
        }

          /* Force Mobile Detail Right Alignment */ @media (max-width: 768px)  {
             .rank-detail-row td.detail-cell  {
                 display:  block  !important;
                 width:  100%  !important;
                 padding:  0  !important;
                 
            }

             .subject-details  {
                 display:  flex  !important;
                 flex-wrap:  wrap  !important;
                 justify-content:  flex-end  !important;
                 align-items:  center  !important;
                 gap:  8px  !important;
                 width:  100%  !important;
                 padding:  12px  !important;
                 box-sizing:  border-box  !important;
                 
            }

             .subject-detail-item  {
                 display:  flex  !important;
                 flex-direction:  row  !important;
                 align-items:  center  !important;
                 justify-content:  space-between  !important;
                 background:  var(--bg-secondary)  !important;
                 border:  1px solid var(--border-color)  !important;
                 padding:  6px 10px  !important;
                 border-radius:  6px  !important;
                 min-width:  90px  !important;
                 width:  auto  !important;
                 flex:  0 0 auto  !important;
                 margin:  0  !important;
                 
            }

             .subject-name  {
                 margin-right:  6px  !important;
                 margin-bottom:  0  !important;
                 
            }

             
        }

          /* Mobile Detail Grid Layout Optimization */ @media (max-width: 768px)  {
             .rank-detail-row td  {
                 padding:  10px  !important;
                 
            }

             .subject-details  {
                 display:  grid  !important;
                 grid-template-columns:  repeat(auto-fit,  minmax(70px,  1fr))  !important;
                 gap:  8px  !important;
                 justify-content:  center  !important;
                 width:  100%;
                 padding:  10px;
                 background:  var(--bg-tertiary);
                 border-radius:  8px;
                 margin:  0 auto;
                 
            }

             .subject-detail-item  {
                 display:  flex  !important;
                 flex-direction:  column  !important;
                 align-items:  center  !important;
                 justify-content:  center  !important;
                 padding:  6px 4px  !important;
                 background:  var(--bg-card);
                 border:  1px solid var(--border-color);
                 border-radius:  6px;
                 width:  auto  !important;
                 min-width:  0  !important;
                 
            }

             .subject-name  {
                 font-size:  12px  !important;
                 color:  var(--text-muted)  !important;
                 margin-bottom:  2px  !important;
                 margin-right:  0  !important;
                 
            }

             .subject-score  {
                 font-size:  14px  !important;
                 font-weight:  bold  !important;
                 color:  var(--text-primary)  !important;
                 
            }

             
        }

          /* Mobile Rank Header Optimization */ @media (max-width: 768px) { .modal-content.modal-large .modal-header { padding: 12px 16px; display: block; position: relative; } .rank-header-controls { display: grid !important; grid-template-columns: 1fr 1fr; gap: 10px; width: 100%; margin-top: 0; } .rank-header-controls h2 { grid-column: 1 / -1; font-size: 18px; margin-bottom: 5px; text-align: left; } .modal-header .modal-close { position: absolute; top: 8px; right: 12px; width: 32px; height: 32px; display: flex; align-items: center; justify-content: center; background: rgba(255, 255, 255, 0.05); border-radius: 50%; z-index: 10; font-size: 20px; } .rank-header-controls select, .rank-header-controls input { width: 100% !important; margin: 0 !important; height: 36px; font-size: 13px; } #rankViewType { grid-column: 1 / 2; } #rankExamSelect { grid-column: 2 / 3; } #rankFilterName { grid-column: 1 / 2; } #rankFilterClass { grid-column: 2 / 3; } #rankFilterType { grid-column: 1 / 2; } #rankAIAnalysisBtn { grid-column: 2 / 3; width: 100% !important; margin: 0 !important; height: 36px; justify-content: center; } }

/* Mobile Rank Table Refinement */ @media (max-width: 768px) { /* ?V?[h?4Y */ .large-table-container { max-height: calc(80vh - 180px) !important; /* ?te??^?N??^[{	?h */ } #bigRankTable thead th { position: sticky; top: 0; z-index: 10; background: var(--bg-card); box-shadow: 0 1px 0 var(--border-color); } /* h?<hUSCQ<hOS */ #bigRankTable th, #bigRankTable td { padding: 12px 4px; font-size: 14px; } /* ?Y
TR */ .student-name-cell { font-weight: 600; font-size: 15px; } /* ;`RR (,{4R) */ #bigRankTable td:nth-child(4) { color: var(--primary-color); font-weight: 700; font-size: 15px; } /* ?c
TR (,{1R) */ #bigRankTable td:first-child { font-family: monospace; font-weight: bold; color: var(--text-secondary); } /* U\_??`?S */ .rank-detail-row td { padding: 0 !important; border: none !important; background: var(--bg-tertiary); } .subject-details { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; padding: 12px 16px; margin: 0; } .subject-detail-item { display: flex; flex-direction: column; align-items: center; justify-content: center; background: var(--bg-card); padding: 8px; border-radius: 8px; box-shadow: 0 2px 4px rgba(0,0,0,0.02); border: 1px solid var(--border-color); } .subject-name { font-size: 12px; color: var(--text-muted); margin-bottom: 4px; } .subject-score { font-size: 16px; font-weight: 600; color: var(--text-primary); font-family: var(--font-mono); } /* vPpeL??of?_? */ #bigRankTable tbody tr:nth-child(4n-3) { background: transparent; } /* ??`L??of */ .rank-detail-row { background: var(--bg-tertiary) !important; } }