/* Mobile-First Responsive Design */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --bg-primary: #ffffff;
    --bg-secondary: #f8fafc;
    --card-bg: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --accent: #3b82f6;
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
    --border: #e2e8f0;
    --shadow: 0 10px 15px -3px rgba(0, 0,0,0.1);
    --shadow-lg: 0 25px 50px -12px rgba(0, 0,0,0.25);
    --radius: 16px;
}

[data-theme="dark"] {
    --bg-primary: #0f172a;
    --bg-secondary: #1e293b;
    --card-bg: #1e293b;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --border: #334155;
}

body {
    font-family: 'Inter', -apple-system, sans-serif;
    background: linear-gradient(135deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
    color: var(--text-primary);
    min-height: 100vh;
    line-height: 1.6;
    overflow-x: hidden; /* Mobile scroll fix */
}

.app {
    max-width: 1400px;
    margin: 0 auto;
    padding: 1rem; /* Reduced padding for mobile */
}

/* Header - Mobile First */
.header {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 1.5rem 1rem; /* Mobile padding */
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 1rem;
}

.header h1 {
    font-size: clamp(1.5rem, 5vw, 2.2rem); /* Responsive font */
    font-weight: 700;
    background: linear-gradient(135deg, var(--accent), #60a5fa);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.header-controls {
    display: flex;
    gap: 0.5rem; /* Reduced gap for mobile */
    align-items: center;
}

.role-select, .theme-toggle {
    padding: 0.6rem 1rem; /* Smaller padding */
    border: 2px solid var(--border);
    border-radius: 12px;
    background: var(--bg-primary);
    color: var(--text-primary);
    font-weight: 500;
    font-size: 0.9rem; /* Smaller font */
    cursor: pointer;
    transition: all 0.3s ease;
    min-width: 80px; /* Minimum width */
}

.role-select:focus, .theme-toggle:hover {
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(59,130,246,0.1);
}

/* Stats Grid - Mobile First */
.stats-grid {
    display: grid;
    grid-template-columns: 1fr; /* Single column mobile */
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.stat-card {
    background: var(--card-bg);
    padding: 1.5rem 1rem; /* Mobile padding */
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

.stat-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.stat-value {
    font-size: clamp(1.8rem, 8vw, 2.5rem); /* Responsive value */
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.stat-income .stat-value { color: var(--success); }
.stat-expense .stat-value { color: var(--danger); }
.stat-balance .stat-value { color: var(--accent); }

.stat-label {
    color: var(--text-secondary);
    font-size: 0.95rem;
    font-weight: 500;
}

/* Charts - Mobile Responsive */
.charts-grid {
    display: grid;
    grid-template-columns: 1fr; /* Single column mobile */
    gap: 1.5rem;
    margin-bottom: 1.5rem;
}

.chart-card {
    background: var(--card-bg);
    padding: 1.5rem 1rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
}

.chart-card h3 {
    margin-bottom: 1rem;
    color: var(--text-primary);
    font-size: 1.1rem;
    font-weight: 600;
    text-align: center;
}

#trendChart, #spendingChart {
    max-height: 280px; /* Smaller for mobile */
    width: 100% !important;
}

/* Filters - Mobile Stacked */
.filters-section {
    background: var(--card-bg);
    padding: 1.5rem 1rem;
    border-radius: var(--radius);
    margin-bottom: 1.5rem;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
}

.filters {
    display: flex;
    flex-direction: column; /* Stacked on mobile */
    gap: 0.75rem;
    align-items: stretch;
}

.filters input, .filters select {
    padding: 0.75rem 1rem;
    border: 2px solid var(--border);
    border-radius: 12px;
    background: var(--bg-primary);
    color: var(--text-primary);
    font-size: 1rem;
}

.filters input:focus, .filters select:focus {
    outline: none;
    border-color: var(--accent);
}

#clearFilters {
    background: var(--accent);
    color: white;
    border: none;
    padding: 0.75rem;
    border-radius: 12px;
    font-weight: 600;
    cursor: pointer;
}

/* Transactions - Mobile Optimized */
.transactions-section {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 1.5rem 1rem;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    margin-bottom: 1.5rem;
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1rem;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.section-header h2 {
    font-size: 1.4rem;
    font-weight: 600;
}

.count {
    background: var(--accent);
    color: white;
    padding: 0.4rem 0.8rem;
    border-radius: 999px;
    font-weight: 600;
    font-size: 0.9rem;
}

.table-container {
    overflow-x: auto;
    margin-bottom: 1.5rem;
    border-radius: 12px;
    -webkit-overflow-scrolling: touch; /* Smooth mobile scroll */
}

table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9rem;
    min-width: 600px; /* Force horizontal scroll on mobile */
}

th, td {
    padding: 0.75rem 0.5rem; /* Smaller padding */
    text-align: left;
    border-bottom: 1px solid var(--border);
    white-space: nowrap; /* Prevent text wrap */
}

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

.income { color: var(--success); font-weight: 600; }
.expense { color: var(--danger); font-weight: 600; }

/* Mobile Action Buttons */
td:last-child button {
    padding: 0.4rem 0.8rem;
    margin: 0 0.2rem;
    border: none;
    border-radius: 6px;
    font-size: 0.8rem;
    cursor: pointer;
}

.edit-btn { background: var(--accent); color: white; }
.delete-btn { background: var(--danger); color: white; }

/* Add Form - Mobile Stacked */
.add-form {
    background: var(--bg-secondary);
    padding: 1.5rem;
    border-radius: var(--radius);
    border: 2px dashed var(--border);
    display: none; /* Hidden by default */
}

.add-form h3 {
    margin-bottom: 1rem;
    font-size: 1.2rem;
}

.form-grid {
    display: flex;
    flex-direction: column; /* Stacked mobile */
    gap: 0.75rem;
}

.form-grid input, .form-grid select {
    padding: 0.75rem;
    border: 2px solid var(--border);
    border-radius: 8px;
    background: var(--bg-primary);
    font-size: 1rem;
}

.form-grid button {
    background: var(--accent);
    color: white;
    border: none;
    padding: 1rem;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    font-size: 1rem;
}

/* Insights */
.insights-section {
    background: var(--card-bg);
    padding: 1.5rem 1rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
}

.insights-grid {
    display: grid;
    grid-template-columns: 1fr; /* Single column mobile */
    gap: 1rem;
    margin-top: 1rem;
}

.insight-card {
    background: linear-gradient(135deg, var(--bg-secondary), var(--bg-primary));
    padding: 1.25rem;
    border-radius: var(--radius);
    border-left: 4px solid var(--accent);
}

/* Animations */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}

.stat-card, .chart-card, .insight-card {
    animation: fadeInUp 0.6s ease forwards;
}

/* ===========================================
   TABLET BREAKPOINTS (768px - 1024px)
============================================ */
@media (min-width: 768px) and (max-width: 1024px) {
    .app { 
        padding: 1.5rem; 
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr); /* 2 columns tablet */
        gap: 1.25rem;
    }
    
    .charts-grid {
        grid-template-columns: 1fr 1fr; /* 2 charts side by side */
    }
    
    .filters {
        flex-direction: row; /* Horizontal filters */
        flex-wrap: wrap;
    }
    
    .filters input, .filters select {
        flex: 1;
        min-width: 120px;
    }
    
    .form-grid {
        grid-template-columns: repeat(2, 1fr); /* 2 column form */
        gap: 1rem;
    }
    
    table {
        min-width: 700px; /* Wider table */
    }
    
    .header {
        padding: 2rem;
    }
}

/* ===========================================
   DESKTOP BREAKPOINTS (1025px+)
============================================ */
@media (min-width: 1025px) {
    .app { 
        padding: 2rem; 
    }
    
    .stats-grid {
        grid-template-columns: repeat(3, 1fr); /* 3 columns desktop */
        gap: 1.5rem;
    }
    
    .charts-grid {
        grid-template-columns: 1fr 1fr;
        gap: 2rem;
    }
    
    .filters {
        flex-direction: row;
        gap: 1rem;
    }
    
    .filters input, .filters select {
        flex: none;
    }
    
    .form-grid {
        grid-template-columns: repeat(4, 1fr);
        gap: 1rem;
    }
    
    table {
        min-width: auto; /* Full width desktop */
    }
    
    .header {
        padding: 2rem;
    }
    
    .header h1 {
        font-size: 2.5rem;
    }
}

/* ===========================================
   MOBILE SPECIFIC OPTIMIZATIONS (<768px)
============================================ */
@media (max-width: 767px) {
    .app { 
        padding: 0.75rem; /* Extra small padding */
    }
    
    .header-content { 
        flex-direction: column; 
        text-align: center; 
        gap: 1rem;
    }
    
    .header-controls {
        order: -1; /* Controls above title on small screens */
        width: 100%;
        justify-content: center;
    }
    
    .section-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 0.5rem;
    }
    
    .add-form {
        padding: 1.25rem;
    }
    
    /* Hide table headers on very small screens, use cards instead */
    @media (max-width: 480px) {
        .table-container table {
            display: none;
        }
        
        .table-container::after {
            content: "📱 Mobile card view coming soon!";
            display: block;
            text-align: center;
            padding: 2rem;
            color: var(--text-secondary);
            font-style: italic;
        }
    }
}

/* iPhone X/12/13/14 notch safe areas */
@supports (padding: max(0px)) {
    body {
        padding-bottom: env(safe-area-inset-bottom);
    }
}