/* ========================================
   DLS Student Performance Dashboard
   Main Styles
   ======================================== */

:root {
    /* Color Palette - Calm & Professional for School */
    --primary-color: #1e2a3a;
    --secondary-color: #2d3e50;
    --accent-color: #3498db;
    --accent-gold: #c9a227;
    --accent-green: #27ae60;
    --accent-blue: #5dade2;
    --text-primary: #ecf0f1;
    --text-secondary: #95a5a6;
    --bg-gradient-start: #1a252f;
    --bg-gradient-mid: #2c3e50;
    --bg-gradient-end: #1e3044;

    /* Card Colors - FIFA Style */
    --card-gold-start: #b8860b;
    --card-gold-mid: #daa520;
    --card-gold-end: #8b6914;
    --card-silver-start: #708090;
    --card-silver-mid: #a8a8a8;
    --card-silver-end: #5a6a7a;
    --card-bronze-start: #8b4513;
    --card-bronze-mid: #a0522d;
    --card-bronze-end: #654321;

    /* Rating Colors - Softer */
    --rating-excellent: #27ae60;
    --rating-good: #58d68d;
    --rating-average: #f4d03f;
    --rating-below: #e67e22;
    --rating-poor: #c0392b;

    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;

    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 16px;
    --radius-xl: 24px;

    /* Shadows */
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.15);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.2);
    --shadow-glow: 0 0 20px rgba(52, 152, 219, 0.2);
}

/* Reset & Base */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Roboto', sans-serif;
    background: linear-gradient(135deg, var(--bg-gradient-start), var(--bg-gradient-mid), var(--bg-gradient-end));
    min-height: 100vh;
    color: var(--text-primary);
    line-height: 1.6;
}

/* App Container */
.app-container {
    max-width: 1600px;
    margin: 0 auto;
    padding: var(--spacing-md);
}

/* Header */
.header {
    background: linear-gradient(90deg, var(--primary-color), var(--secondary-color));
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    box-shadow: var(--shadow-lg);
    border: 1px solid rgba(255, 255, 255, 0.1);
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: var(--spacing-md);
}

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

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

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

.logo-icon {
    font-family: 'Oswald', sans-serif;
    font-size: 3rem;
    font-weight: 700;
    color: var(--accent-gold);
    background: linear-gradient(135deg, #c9a227 0%, #f4d03f 50%, #c9a227 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    padding: var(--spacing-sm) var(--spacing-md);
    border: 2px solid var(--accent-gold);
    border-radius: var(--radius-md);
}

.header-titles {
    text-align: left;
}

.title {
    font-family: 'Oswald', sans-serif;
    font-size: 1.8rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 3px;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.subtitle {
    font-family: 'Roboto', sans-serif;
    font-size: 1rem;
    font-weight: 400;
    color: var(--text-secondary);
    letter-spacing: 1px;
}

/* Navigation Tabs */
.nav-tabs {
    display: flex;
    justify-content: center;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
    margin-bottom: var(--spacing-lg);
    padding: var(--spacing-sm);
    background: rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-lg);
    backdrop-filter: blur(10px);
}

.tab-btn {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-xl);
    background: transparent;
    border: none;
    border-bottom: 3px solid transparent;
    border-radius: 0;
    color: var(--text-secondary);
    font-family: 'Oswald', sans-serif;
    font-size: 0.95rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 1px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.tab-icon {
    font-size: 1.1rem;
}

.tab-text {
    white-space: nowrap;
}

.tab-btn:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
}

.tab-btn.active {
    color: var(--accent-gold);
    border-bottom-color: var(--accent-gold);
    background: rgba(201, 162, 39, 0.1);
}

/* Filters Section */
.filters-section {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--spacing-md);
    flex-wrap: wrap;
    margin-bottom: var(--spacing-lg);
    padding: var(--spacing-md);
    background: rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-md);
    backdrop-filter: blur(10px);
}

.search-box {
    position: relative;
    flex: 1;
    min-width: 250px;
    max-width: 400px;
}

.search-box input {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-lg);
    padding-left: 50px;
    background: rgba(255, 255, 255, 0.1);
    border: 2px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 1rem;
    transition: all 0.3s ease;
}

.search-box input:focus {
    outline: none;
    border-color: var(--accent-gold);
    background: rgba(255, 255, 255, 0.15);
}

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

.search-icon {
    position: absolute;
    left: var(--spacing-md);
    top: 50%;
    transform: translateY(-50%);
    font-size: 1.2rem;
}

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

.filter-group {
    display: flex;
    gap: var(--spacing-sm);
    align-items: center;
}

.filter-actions {
    display: flex;
    gap: var(--spacing-sm);
    align-items: center;
}

.filter-group select {
    padding: var(--spacing-md) var(--spacing-lg);
    background: rgba(255, 255, 255, 0.1);
    border: 2px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    color: var(--text-primary);
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
}

.filter-group select:focus {
    outline: none;
    border-color: var(--accent-gold);
}

.filter-group select option {
    background: var(--primary-color);
    color: var(--text-primary);
}

.refresh-btn {
    padding: var(--spacing-md) var(--spacing-lg);
    background: linear-gradient(135deg, var(--accent-gold), #e5a96a);
    border: none;
    border-radius: var(--radius-md);
    color: var(--primary-color);
    font-family: 'Oswald', sans-serif;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}

.refresh-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(255, 215, 0, 0.4);
}

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

.refresh-btn.loading {
    opacity: 0.7;
    pointer-events: none;
}

.refresh-btn.loading::after {
    content: '';
    display: inline-block;
    width: 12px;
    height: 12px;
    border: 2px solid var(--primary-color);
    border-top-color: transparent;
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
    margin-left: 8px;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

/* Sync Status Indicator */
.sync-status {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-sm) var(--spacing-md);
    background: rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-md);
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.sync-status.success .status-text {
    color: var(--rating-excellent);
}

.sync-status.error .status-text {
    color: var(--rating-poor);
}

.sync-status.loading .status-icon {
    animation: spin 1s linear infinite;
}

.status-icon {
    font-size: 0.9rem;
}

/* Notification Toast */
.sheets-notification {
    position: fixed;
    bottom: 20px;
    right: 20px;
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-lg);
    background: var(--secondary-color);
    border-radius: var(--radius-md);
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
    z-index: 9999;
    animation: slideIn 0.3s ease;
    border-left: 4px solid var(--accent-blue);
}

.sheets-notification.success {
    border-left-color: var(--rating-excellent);
}

.sheets-notification.error {
    border-left-color: var(--rating-poor);
}

.sheets-notification.fade-out {
    opacity: 0;
    transform: translateX(20px);
    transition: all 0.3s ease;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.notification-icon {
    font-size: 1.2rem;
}

.notification-text {
    color: var(--text-primary);
    font-size: 0.9rem;
}

/* Main Content */
.main-content {
    min-height: 60vh;
}

.tab-content {
    display: none;
    animation: fadeIn 0.3s ease;
}

.tab-content.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-xl);
}

.section-header h2 {
    font-family: 'Oswald', sans-serif;
    font-size: 2rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 3px;
    margin-bottom: var(--spacing-sm);
    color: var(--accent-gold);
}

.section-header p {
    color: var(--text-secondary);
    font-size: 1rem;
}

/* Cards Grid */
.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--spacing-lg);
    padding: var(--spacing-md);
}

/* Stats Content Layout */
.stats-content {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
}

.stats-overview {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-md);
    justify-content: center;
}

.summary-cards {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-md);
    justify-content: center;
}

.summary-card {
    background: linear-gradient(135deg, var(--secondary-color), var(--primary-color));
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    padding: var(--spacing-lg);
    min-width: 150px;
    text-align: center;
    transition: transform 0.3s ease;
}

.summary-card:hover {
    transform: translateY(-5px);
}

.summary-card .value {
    font-family: 'Oswald', sans-serif;
    font-size: 2rem;
    font-weight: 700;
    color: var(--accent-gold);
}

.summary-card .label {
    font-size: 0.9rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.8);
    z-index: 1000;
    backdrop-filter: blur(5px);
    overflow-y: auto;
    padding: var(--spacing-lg);
}

.modal.active {
    display: flex;
    justify-content: center;
    align-items: flex-start;
}

.modal-content {
    background: linear-gradient(135deg, var(--secondary-color), var(--primary-color));
    border-radius: var(--radius-lg);
    max-width: 1000px;
    width: 100%;
    margin: var(--spacing-xl) auto;
    position: relative;
    box-shadow: var(--shadow-lg);
    border: 1px solid rgba(255, 255, 255, 0.1);
}

.close-btn {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    font-size: 2rem;
    color: var(--text-secondary);
    cursor: pointer;
    transition: color 0.3s ease;
    z-index: 10;
}

.close-btn:hover {
    color: var(--accent-color);
}

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

/* Footer */
.footer {
    text-align: center;
    padding: var(--spacing-xl) var(--spacing-md);
    margin-top: var(--spacing-xl);
    color: var(--text-secondary);
    font-size: 0.9rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

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

::-webkit-scrollbar-track {
    background: var(--primary-color);
}

::-webkit-scrollbar-thumb {
    background: var(--accent-gold);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--accent-color);
}

/* Language Switcher */
.lang-switcher {
    display: flex;
    gap: 4px;
    margin-right: var(--spacing-md);
    background: rgba(255, 255, 255, 0.1);
    border-radius: var(--radius-md);
    padding: 3px;
}

.lang-btn {
    padding: 6px 12px;
    background: transparent;
    border: none;
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    font-family: 'Oswald', sans-serif;
    font-size: 0.85rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

.lang-btn:hover {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.1);
}

.lang-btn.active {
    background: var(--accent-gold);
    color: var(--primary-color);
}

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

/* Responsive */
@media (max-width: 768px) {
    .title {
        font-size: 1.5rem;
        letter-spacing: 2px;
    }

    .nav-tabs {
        gap: var(--spacing-xs);
    }

    .tab-btn {
        padding: var(--spacing-sm) var(--spacing-md);
        font-size: 0.85rem;
    }

    .tab-icon {
        display: none;
    }

    .filters-section {
        flex-direction: column;
    }

    .search-box {
        max-width: 100%;
    }

    .cards-grid {
        grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
        gap: var(--spacing-md);
    }
}

@media (max-width: 480px) {
    .app-container {
        padding: var(--spacing-sm);
    }

    .header {
        padding: var(--spacing-md);
    }

    .logo-text {
        display: none;
    }

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