style.css

/* ============================================
   CRYPTO PRICE TRACKER V2.0 - MAIN STYLES
   Dark/Light Theme | Responsive | Modern Design
   ============================================ */

/* ============================================
   CSS VARIABLES (Dark Theme Default)
   ============================================ */
:root {
    /* Dark Theme Colors */
    --bg-primary: #0a0a0f;
    --bg-secondary: #1a1a2e;
    --bg-tertiary: #16213e;
    --bg-card: rgba(26, 26, 46, 0.95);
    --text-primary: #ffffff;
    --text-secondary: #a0a0b0;
    --text-muted: #6c6c7a;
    --border-color: rgba(255, 255, 255, 0.08);
    
    /* Accent Colors */
    --accent-primary: #00d4ff;
    --accent-secondary: #7b2cbf;
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
    --info: #3b82f6;
    
    /* Gradients */
    --gradient-primary: linear-gradient(135deg, var(--accent-primary), var(--accent-secondary));
    --gradient-success: linear-gradient(135deg, #10b981, #059669);
    --gradient-danger: linear-gradient(135deg, #ef4444, #dc2626);
    
    /* Spacing */
    --sidebar-width: 260px;
    --header-height: 70px;
    --border-radius: 16px;
    --border-radius-sm: 8px;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
}

/* Light Theme Variables */
[data-theme="light"] {
    --bg-primary: #f5f7fb;
    --bg-secondary: #ffffff;
    --bg-tertiary: #f8fafc;
    --bg-card: #ffffff;
    --text-primary: #1a1a2e;
    --text-secondary: #4a4a5a;
    --text-muted: #94a3b8;
    --border-color: rgba(0, 0, 0, 0.08);
}

/* ============================================
   RESET & BASE STYLES
   ============================================ */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.5;
    overflow-x: hidden;
    transition: background-color var(--transition-normal);
}

/* ============================================
   LOADING OVERLAY
   ============================================ */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--bg-primary);
    z-index: 9999;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    transition: opacity 0.5s ease;
}

.loading-overlay.hide {
    opacity: 0;
    pointer-events: none;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 3px solid var(--border-color);
    border-top-color: var(--accent-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

/* ============================================
   TOAST NOTIFICATIONS
   ============================================ */
.toast-container {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 10000;
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.toast {
    background: var(--bg-card);
    backdrop-filter: blur(10px);
    border-left: 4px solid var(--accent-primary);
    border-radius: var(--border-radius-sm);
    padding: 12px 20px;
    min-width: 280px;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.2);
    animation: slideInRight 0.3s ease;
}

.toast.success { border-left-color: var(--success); }
.toast.error { border-left-color: var(--danger); }
.toast.warning { border-left-color: var(--warning); }

.toast-content {
    display: flex;
    align-items: center;
    gap: 12px;
}

.toast i { font-size: 1.2rem; }
.toast.success i { color: var(--success); }
.toast.error i { color: var(--danger); }

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

/* ============================================
   APP CONTAINER & SIDEBAR
   ============================================ */
.app-container {
    display: flex;
    min-height: 100vh;
}

.sidebar {
    width: var(--sidebar-width);
    background: var(--bg-secondary);
    border-right: 1px solid var(--border-color);
    display: flex;
    flex-direction: column;
    position: fixed;
    left: 0;
    top: 0;
    bottom: 0;
    transition: transform var(--transition-normal);
    z-index: 100;
}

.sidebar.collapsed {
    transform: translateX(-100%);
}

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

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.4rem;
    font-weight: 700;
}

.logo i {
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    background-clip: text;
    color: transparent;
}

.logo .highlight {
    color: var(--accent-primary);
}

.sidebar-toggle {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 1.2rem;
    display: none;
}

.sidebar-nav {
    flex: 1;
    padding: 20px 0;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.nav-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 20px;
    color: var(--text-secondary);
    text-decoration: none;
    transition: all var(--transition-fast);
    position: relative;
}

.nav-item:hover {
    background: rgba(0, 212, 255, 0.1);
    color: var(--accent-primary);
}

.nav-item.active {
    background: linear-gradient(90deg, rgba(0, 212, 255, 0.15), transparent);
    color: var(--accent-primary);
    border-right: 3px solid var(--accent-primary);
}

.nav-item i {
    width: 20px;
    font-size: 1.1rem;
}

.nav-item .badge {
    background: var(--accent-primary);
    color: white;
    font-size: 0.7rem;
    padding: 2px 6px;
    border-radius: 10px;
    margin-left: auto;
}

.sidebar-footer {
    padding: 20px;
    border-top: 1px solid var(--border-color);
    font-size: 0.8rem;
    display: flex;
    justify-content: space-between;
}

.market-status {
    display: flex;
    align-items: center;
    gap: 6px;
}

.market-status i {
    font-size: 0.6rem;
}

.market-status i.online {
    color: var(--success);
}

/* ============================================
   MAIN CONTENT
   ============================================ */
.main-content {
    flex: 1;
    margin-left: var(--sidebar-width);
    transition: margin-left var(--transition-normal);
}

.sidebar.collapsed ~ .main-content {
    margin-left: 0;
}

/* Top Header */
.top-header {
    background: var(--bg-secondary);
    padding: 15px 30px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 90;
}

.header-left h1 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 4px;
}

.last-updated {
    font-size: 0.75rem;
    color: var(--text-muted);
    display: flex;
    align-items: center;
    gap: 6px;
}

.header-right {
    display: flex;
    align-items: center;
    gap: 15px;
}

.search-container {
    position: relative;
}

.search-container input {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 30px;
    padding: 10px 20px 10px 40px;
    color: var(--text-primary);
    width: 250px;
    transition: width var(--transition-fast);
}

.search-container input:focus {
    width: 300px;
    outline: none;
    border-color: var(--accent-primary);
}

.search-container i {
    position: absolute;
    left: 15px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
}

.search-results {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--bg-card);
    border-radius: var(--border-radius-sm);
    border: 1px solid var(--border-color);
    max-height: 300px;
    overflow-y: auto;
    display: none;
    z-index: 100;
}

.search-results.show {
    display: block;
}

.search-result-item {
    padding: 10px 15px;
    cursor: pointer;
    transition: background var(--transition-fast);
}

.search-result-item:hover {
    background: rgba(0, 212, 255, 0.1);
}

.theme-toggle, .refresh-btn {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--text-primary);
    transition: all var(--transition-fast);
}

.theme-toggle:hover, .refresh-btn:hover {
    background: var(--accent-primary);
    color: white;
}

/* ============================================
   PAGE CONTAINERS
   ============================================ */
.page {
    padding: 25px 30px;
    display: none;
    animation: fadeIn 0.3s ease;
}

.page.active {
    display: block;
}

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

.page-header {
    margin-bottom: 25px;
}

.page-header h2 {
    font-size: 1.6rem;
    font-weight: 600;
    margin-bottom: 8px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.page-header p {
    color: var(--text-muted);
}

/* ============================================
   STATS GRID
   ============================================ */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 20px;
    margin-bottom: 30px;
}

.stat-card {
    background: var(--bg-card);
    border-radius: var(--border-radius);
    padding: 20px;
    display: flex;
    align-items: center;
    gap: 15px;
    border: 1px solid var(--border-color);
    transition: transform var(--transition-fast);
}

.stat-card:hover {
    transform: translateY(-2px);
}

.stat-icon {
    width: 50px;
    height: 50px;
    background: rgba(0, 212, 255, 0.1);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    color: var(--accent-primary);
}

.stat-info {
    flex: 1;
}

.stat-label {
    font-size: 0.8rem;
    color: var(--text-muted);
    display: block;
    margin-bottom: 5px;
}

.stat-value {
    font-size: 1.5rem;
    font-weight: 700;
}

.stat-change {
    font-size: 0.75rem;
    margin-left: 8px;
}

.stat-change.positive { color: var(--success); }
.stat-change.negative { color: var(--danger); }

/* ============================================
   TRENDING SECTION
   ============================================ */
.trending-section {
    margin-bottom: 30px;
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    flex-wrap: wrap;
    gap: 15px;
}

.section-header h2 {
    font-size: 1.2rem;
    font-weight: 600;
}

.section-tabs {
    display: flex;
    gap: 10px;
}

.tab-btn {
    background: none;
    border: none;
    padding: 8px 16px;
    border-radius: 20px;
    cursor: pointer;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.tab-btn.active {
    background: var(--gradient-primary);
    color: white;
}

.trending-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
}

.trending-card {
    background: var(--bg-card);
    border-radius: var(--border-radius);
    padding: 15px;
    border: 1px solid var(--border-color);
    transition: transform var(--transition-fast);
}

.trending-card:hover {
    transform: translateY(-2px);
}

.trending-card .symbol {
    font-weight: 700;
    font-size: 1rem;
}

.trending-card .price {
    font-size: 1.2rem;
    font-weight: 700;
    margin: 8px 0;
}

.trending-card .change {
    font-size: 0.8rem;
    font-weight: 500;
}

.change.positive { color: var(--success); }
.change.negative { color: var(--danger); }

/* ============================================
   CHART SECTION
   ============================================ */
.chart-section {
    background: var(--bg-card);
    border-radius: var(--border-radius);
    padding: 20px;
    margin-bottom: 30px;
    border: 1px solid var(--border-color);
}

.chart-container {
    height: 300px;
    position: relative;
}

.chart-controls {
    display: flex;
    gap: 8px;
}

.chart-time-btn {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    padding: 5px 12px;
    border-radius: 15px;
    cursor: pointer;
    color: var(--text-secondary);
    transition: all var(--transition-fast);
}

.chart-time-btn.active {
    background: var(--accent-primary);
    color: white;
}

/* ============================================
   TABLE STYLES
   ============================================ */
.table-section {
    background: var(--bg-card);
    border-radius: var(--border-radius);
    border: 1px solid var(--border-color);
    overflow: hidden;
}

.table-container {
    overflow-x: auto;
}

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

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

.crypto-table th {
    font-weight: 600;
    color: var(--text-muted);
    cursor: pointer;
    user-select: none;
}

.crypto-table th:hover {
    color: var(--accent-primary);
}

.crypto-table tbody tr {
    transition: background var(--transition-fast);
}

.crypto-table tbody tr:hover {
    background: rgba(0, 212, 255, 0.05);
}

.coin-cell {
    display: flex;
    align-items: center;
    gap: 12px;
}

.coin-cell img {
    width: 30px;
    height: 30px;
}

.coin-name {
    font-weight: 600;
}

.coin-symbol {
    font-size: 0.75rem;
    color: var(--text-muted);
    display: block;
}

.price-cell {
    font-weight: 600;
}

.change-cell.positive {
    color: var(--success);
}

.change-cell.negative {
    color: var(--danger);
}

.volume-cell, .marketcap-cell {
    font-size: 0.85rem;
}

.watchlist-btn {
    background: none;
    border: none;
    cursor: pointer;
    color: var(--text-muted);
    font-size: 1.1rem;
    transition: color var(--transition-fast);
}

.watchlist-btn:hover {
    color: var(--warning);
}

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

/* ============================================
   PAGINATION
   ============================================ */
.pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 20px;
    padding: 20px;
}

.page-btn {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    padding: 8px 16px;
    border-radius: var(--border-radius-sm);
    cursor: pointer;
    color: var(--text-primary);
    transition: all var(--transition-fast);
}

.page-btn:hover:not(:disabled) {
    background: var(--accent-primary);
    color: white;
}

.page-btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* ============================================
   WATCHLIST PAGE
   ============================================ */
.watchlist-container {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.watchlist-item {
    background: var(--bg-card);
    border-radius: var(--border-radius);
    padding: 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border: 1px solid var(--border-color);
}

.watchlist-item-info {
    display: flex;
    align-items: center;
    gap: 15px;
}

.watchlist-item-symbol {
    font-weight: 700;
    font-size: 1.1rem;
}

.watchlist-item-price {
    font-weight: 600;
}

.empty-watchlist {
    text-align: center;
    padding: 50px;
    color: var(--text-muted);
}

/* ============================================
   ALERTS PAGE
   ============================================ */
.create-alert-card {
    background: var(--bg-card);
    border-radius: var(--border-radius);
    padding: 25px;
    margin-bottom: 25px;
    border: 1px solid var(--border-color);
}

.alert-form {
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
    margin-top: 15px;
}

.alert-input {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    padding: 12px 16px;
    border-radius: var(--border-radius-sm);
    color: var(--text-primary);
    min-width: 150px;
}

.btn-primary {
    background: var(--gradient-primary);
    border: none;
    padding: 12px 24px;
    border-radius: var(--border-radius-sm);
    color: white;
    font-weight: 600;
    cursor: pointer;
    transition: transform var(--transition-fast);
}

.btn-primary:hover {
    transform: scale(1.02);
}

.alerts-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.alert-item {
    background: var(--bg-card);
    border-radius: var(--border-radius);
    padding: 15px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border: 1px solid var(--border-color);
}

.delete-alert-btn {
    background: none;
    border: none;
    color: var(--danger);
    cursor: pointer;
    font-size: 1rem;
}

/* ============================================
   SETTINGS PAGE
   ============================================ */
.settings-container {
    max-width: 600px;
}

.settings-section {
    background: var(--bg-card);
    border-radius: var(--border-radius);
    padding: 20px;
    margin-bottom: 20px;
    border: 1px solid var(--border-color);
}

.settings-section h3 {
    margin-bottom: 15px;
    font-size: 1rem;
}

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

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

.setting-item label {
    font-size: 0.9rem;
}

.theme-options {
    display: flex;
    gap: 10px;
}

.theme-option {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    padding: 6px 12px;
    border-radius: 20px;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.theme-option.active {
    background: var(--accent-primary);
    color: white;
}

.btn-secondary {
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    padding: 8px 16px;
    border-radius: var(--border-radius-sm);
    cursor: pointer;
    color: var(--text-primary);
    transition: all var(--transition-fast);
}

.btn-secondary:hover {
    background: var(--accent-primary);
    color: white;
}

/* ============================================
   ANALYTICS PAGE
   ============================================ */
.analytics-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.analytics-card {
    background: var(--bg-card);
    border-radius: var(--border-radius);
    padding: 20px;
    border: 1px solid var(--border-color);
}

.analytics-card.full-width {
    grid-column: span 2;
}

.analytics-select {
    width: 100%;
    padding: 10px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-sm);
    color: var(--text-primary);
    margin-top: 10px;
}

.metrics-list {
    margin-top: 15px;
}

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

/* ============================================
   RESPONSIVE DESIGN
   ============================================ */
@media (max-width: 1024px) {
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .analytics-grid {
        grid-template-columns: 1fr;
    }
    
    .analytics-card.full-width {
        grid-column: span 1;
    }
}

@media (max-width: 768px) {
    .sidebar {
        transform: translateX(-100%);
    }
    
    .sidebar.open {
        transform: translateX(0);
    }
    
    .sidebar-toggle {
        display: block;
    }
    
    .main-content {
        margin-left: 0;
    }
    
    .top-header {
        flex-direction: column;
        gap: 15px;
        align-items: stretch;
    }
    
    .header-right {
        justify-content: space-between;
    }
    
    .search-container input {
        width: 100%;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .page {
        padding: 20px 15px;
    }
    
    .alert-form {
        flex-direction: column;
    }
    
    .alert-input {
        width: 100%;
    }
    
    .crypto-table th,
    .crypto-table td {
        padding: 10px;
        font-size: 0.8rem;
    }
}

@media (max-width: 480px) {
    .trending-grid {
        grid-template-columns: 1fr;
    }
    
    .section-header {
        flex-direction: column;
        align-items: flex-start;
    }
}

/* ============================================
   UTILITY CLASSES
   ============================================ */
.text-success { color: var(--success); }
.text-danger { color: var(--danger); }
.text-warning { color: var(--warning); }
.text-info { color: var(--info); }
.text-muted { color: var(--text-muted); }

.mt-2 { margin-top: 8px; }
.mt-3 { margin-top: 12px; }
.mt-4 { margin-top: 16px; }
.mb-2 { margin-bottom: 8px; }
.mb-3 { margin-bottom: 12px; }
.mb-4 { margin-bottom: 16px; }

.loading-cell {
    text-align: center;
    padding: 40px !important;
    color: var(--text-muted);
}

.error-cell {
    text-align: center;
    padding: 40px !important;
    color: var(--danger);
}