/* Root Variables for Color System */
:root {
    /* Primitive Color Tokens */
    --color-white: rgba(255, 255, 255, 1);
    --color-black: rgba(0, 0, 0, 1);
    --color-cream-50: rgba(252, 252, 249, 1);
    --color-cream-100: rgba(255, 255, 253, 1);
    --color-gray-200: rgba(245, 245, 245, 1);
    --color-gray-300: rgba(167, 169, 169, 1);
    --color-gray-400: rgba(119, 124, 124, 1);
    --color-slate-500: rgba(98, 108, 113, 1);
    --color-brown-600: rgba(94, 82, 64, 1);
    --color-charcoal-700: rgba(31, 33, 33, 1);
    --color-charcoal-800: rgba(38, 40, 40, 1);
    --color-slate-900: rgba(19, 52, 59, 1);
    --color-teal-300: rgba(50, 184, 198, 1);
    --color-teal-400: rgba(45, 166, 178, 1);
    --color-teal-500: rgba(33, 128, 141, 1);
    --color-teal-600: rgba(29, 116, 128, 1);
    --color-teal-700: rgba(26, 104, 115, 1);
    --color-teal-800: rgba(41, 150, 161, 1);
    --color-red-400: rgba(255, 84, 89, 1);
    --color-red-500: rgba(192, 21, 47, 1);
    --color-orange-400: rgba(230, 129, 97, 1);
    --color-orange-500: rgba(168, 75, 47, 1);

    /* RGB versions for opacity control */
    --color-brown-600-rgb: 94, 82, 64;
    --color-teal-500-rgb: 33, 128, 141;
    --color-slate-900-rgb: 19, 52, 59;
    --color-slate-500-rgb: 98, 108, 113;

    /* Semantic Color Tokens */
    --color-background: var(--color-cream-100);
    --color-surface: var(--color-white);
    --color-surface-alt: var(--color-cream-50);
    --color-text-primary: var(--color-slate-900);
    --color-text-secondary: var(--color-slate-500);
    --color-text-tertiary: var(--color-gray-400);
    --color-text-inverse: var(--color-white);

    /* Functional Colors */
    --color-primary: var(--color-teal-600);
    --color-primary-hover: var(--color-teal-700);
    --color-primary-light: var(--color-teal-300);
    --color-secondary: var(--color-brown-600);
    --color-secondary-hover: rgba(var(--color-brown-600-rgb), 0.8);

    /* Status Colors */
    --color-success: var(--color-teal-500);
    --color-success-bg: rgba(var(--color-teal-500-rgb), 0.1);
    --color-warning: var(--color-orange-400);
    --color-warning-bg: rgba(230, 129, 97, 0.1);
    --color-danger: var(--color-red-400);
    --color-danger-bg: rgba(255, 84, 89, 0.1);
    --color-info: var(--color-teal-400);
    --color-info-bg: rgba(45, 166, 178, 0.1);

    /* Border & Divider Colors */
    --color-border: var(--color-gray-200);
    --color-border-light: rgba(var(--color-slate-500-rgb), 0.1);
    --color-divider: rgba(var(--color-slate-500-rgb), 0.15);

    /* Shadow Colors */
    --shadow-soft: 0 2px 8px rgba(var(--color-slate-900-rgb), 0.08);
    --shadow-medium: 0 4px 12px rgba(var(--color-slate-900-rgb), 0.12);
    --shadow-strong: 0 8px 24px rgba(var(--color-slate-900-rgb), 0.15);
    --shadow-overlay: 0 16px 48px rgba(var(--color-slate-900-rgb), 0.2);
}

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

html {
    font-size: 16px;
    line-height: 1.6;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: var(--color-background);
    color: var(--color-text-primary);
    overflow-x: hidden;
    min-height: 100vh;
}

/* Typography Scale */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.3;
    margin-bottom: 0.5em;
    color: var(--color-text-primary);
}

h1 { font-size: clamp(1.5rem, 4vw, 2rem); }
h2 { font-size: clamp(1.25rem, 3vw, 1.75rem); }
h3 { font-size: clamp(1.125rem, 2.5vw, 1.5rem); }
h4 { font-size: clamp(1rem, 2vw, 1.25rem); }

p {
    margin-bottom: 1em;
    color: var(--color-text-secondary);
}

/* Container & Layout */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem;
}

@media (min-width: 768px) {
    .container {
        padding: 2rem 1rem;
    }
}

/* Header with Navigation */
.header {
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow-soft);
    position: sticky;
    top: 0;
    z-index: 100;
    margin-bottom: 2rem;
}

.header h1 {
    font-size: clamp(1.25rem, 3vw, 1.75rem);
    color: var(--color-primary);
    margin: 0 0 1rem 0;
    text-align: center;
}

.nav {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    justify-content: center;
    padding: 1rem;
}

.nav a {
    padding: 0.5rem 1rem;
    text-decoration: none;
    color: var(--color-text-secondary);
    background: var(--color-surface-alt);
    border-radius: 6px;
    font-weight: 500;
    transition: all 0.2s ease;
    white-space: nowrap;
}

.nav a:hover {
    color: var(--color-primary);
    background: rgba(var(--color-teal-500-rgb), 0.1);
}

.nav a.active {
    color: var(--color-text-inverse);
    background: var(--color-primary);
}

.nav a.logout {
    color: var(--color-danger);
    margin-left: auto;
}

@media (min-width: 768px) {
    .nav {
        gap: 1rem;
        padding: 1rem 2rem;
    }

    .nav a {
        padding: 0.75rem 1.5rem;
    }
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1rem;
    margin-bottom: 2rem;
}

@media (min-width: 480px) {
    .stats-grid {
        grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    }
}

.stat-card {
    background: var(--color-surface);
    border-radius: 12px;
    padding: 1.5rem;
    box-shadow: var(--shadow-soft);
    text-align: center;
    position: relative;
    overflow: hidden;
}

.stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--color-primary), var(--color-primary-light));
}

.stat-card h3 {
    color: var(--color-text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
    text-transform: uppercase;
    margin-bottom: 0.5rem;
}

.stat-card .value {
    font-size: clamp(1.5rem, 4vw, 2rem);
    font-weight: 700;
    color: var(--color-text-primary);
    margin-bottom: 0.25rem;
}

.stat-card .change {
    color: var(--color-text-tertiary);
    font-size: 0.85rem;
}

.stat-card .text-success { color: var(--color-success); }
.stat-card .text-danger { color: var(--color-danger); }

/* Cards */
.card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 12px;
    box-shadow: var(--shadow-soft);
    margin-bottom: 1.5rem;
    overflow: hidden;
}

.card-header {
    padding: 1rem 1.5rem;
    border-bottom: 1px solid var(--color-border);
    background: var(--color-surface-alt);
}

.card-header h2 {
    margin: 0;
    font-size: clamp(1.125rem, 2.5vw, 1.5rem);
    color: var(--color-text-primary);
}

.card-body {
    padding: 1.5rem;
}

/* Forms */
.form-group {
    margin-bottom: 1rem;
}

.form-group label {
    display: block;
    font-weight: 500;
    color: var(--color-text-primary);
    margin-bottom: 0.5rem;
    font-size: 0.9rem;
}

.form-control {
    width: 100%;
    padding: 0.75rem;
    border: 2px solid var(--color-border);
    border-radius: 8px;
    font-size: 1rem;
    background: var(--color-surface);
    color: var(--color-text-primary);
    transition: all 0.2s ease;
}

.form-control:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(var(--color-teal-500-rgb), 0.1);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1rem;
}

@media (min-width: 768px) {
    .form-row {
        grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    }
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    font-size: 0.9rem;
    font-weight: 500;
    text-decoration: none;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.2s ease;
    min-height: 44px;
    white-space: nowrap;
}

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

.btn-primary:hover {
    background: var(--color-primary-hover);
    transform: translateY(-1px);
    box-shadow: var(--shadow-medium);
}

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

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

.btn-danger {
    background: var(--color-danger);
    color: var(--color-text-inverse);
    border: 1px solid var(--color-danger);
}

.btn-danger:hover {
    background: var(--color-red-500);
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.8rem;
    min-height: 36px;
}

.btn-export {
    background: var(--color-success);
    color: var(--color-text-inverse);
    border: 1px solid var(--color-success);
}

.btn-export:hover {
    background: var(--color-teal-700);
}

/* Alerts */
.alert {
    padding: 1rem;
    border-radius: 8px;
    margin-bottom: 1.5rem;
    border: 1px solid transparent;
}

.alert-success {
    background: var(--color-success-bg);
    border-color: rgba(var(--color-teal-500-rgb), 0.2);
    color: var(--color-success);
}

.alert-error, .alert-danger {
    background: var(--color-danger-bg);
    border-color: rgba(255, 84, 89, 0.2);
    color: var(--color-danger);
}

/* Tables - Mobile First Responsive */
.table-responsive {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
}

table {
    width: 100%;
    min-width: 600px;
    border-collapse: collapse;
    background: var(--color-surface);
    border-radius: 8px;
    overflow: hidden;
    box-shadow: var(--shadow-soft);
}

table th {
    background: var(--color-surface-alt);
    color: var(--color-text-primary);
    font-weight: 600;
    padding: 0.75rem;
    text-align: left;
    border-bottom: 2px solid var(--color-border);
    font-size: 0.85rem;
    text-transform: uppercase;
    white-space: nowrap;
}

table td {
    padding: 0.75rem;
    border-bottom: 1px solid var(--color-border-light);
    color: var(--color-text-secondary);
    vertical-align: middle;
}

table .amount {
    font-weight: 600;
    color: var(--color-text-primary);
    text-align: right;
    white-space: nowrap;
}

table tr:hover {
    background: var(--color-surface-alt);
}

/* Budget Overview Cards - Mobile Optimized */
.budget-overview-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: 12px;
    padding: 1rem;
    margin-bottom: 1rem;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.budget-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.budget-name {
    font-weight: 600;
    color: var(--color-text-primary);
    font-size: 1rem;
}

.budget-type {
    background: var(--color-surface-alt);
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-size: 0.75rem;
    color: var(--color-text-secondary);
}

.budget-amounts {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.budget-spent {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-text-primary);
}

.budget-total {
    font-size: 0.9rem;
    color: var(--color-text-secondary);
}

.budget-progress {
    width: 100%;
}

.progress-bar {
    background: var(--color-border-light);
    border-radius: 4px;
    height: 8px;
    overflow: hidden;
    margin-bottom: 0.5rem;
}

.progress-fill {
    height: 100%;
    border-radius: 4px;
    transition: width 0.3s ease;
}

.progress-fill.good {
    background: var(--color-success);
}

.progress-fill.warning {
    background: var(--color-warning);
}

.progress-fill.over-budget {
    background: var(--color-danger);
}

.progress-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.85rem;
    color: var(--color-text-secondary);
}

/* Budget Selection Info */
.budget-info {
    background: var(--color-info-bg);
    border: 1px solid rgba(45, 166, 178, 0.2);
    border-radius: 8px;
    padding: 1rem;
    margin-top: 0.5rem;
    display: none;
}

.budget-info.show {
    display: block;
}

.budget-info h4 {
    margin: 0 0 0.5rem 0;
    color: var(--color-info);
    font-size: 1rem;
}

.budget-info .info-row {
    display: flex;
    justify-content: space-between;
    margin-bottom: 0.25rem;
    font-size: 0.9rem;
}

/* Login Page */
.login-container {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1rem;
}

.login-card {
    background: var(--color-surface);
    border-radius: 16px;
    box-shadow: var(--shadow-strong);
    width: 100%;
    max-width: 420px;
    padding: 2rem;
}

.login-header {
    text-align: center;
    margin-bottom: 2rem;
}

.login-header h1 {
    color: var(--color-primary);
    margin-bottom: 0.5rem;
    font-size: clamp(1.5rem, 4vw, 2rem);
}

.demo-info {
    background: var(--color-info-bg);
    border: 1px solid rgba(45, 166, 178, 0.2);
    border-radius: 8px;
    padding: 1rem;
    margin-bottom: 1.5rem;
}

.demo-credentials {
    margin: 0.5rem 0;
}

.demo-credentials p {
    margin: 0.25rem 0;
    font-size: 0.9rem;
}

.login-tabs {
    display: flex;
    background: var(--color-surface-alt);
    border-radius: 8px;
    padding: 4px;
    margin-bottom: 1.5rem;
}

.tab-btn {
    flex: 1;
    padding: 0.75rem;
    background: transparent;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    font-weight: 500;
    color: var(--color-text-secondary);
    transition: all 0.2s ease;
}

.tab-btn.active {
    background: var(--color-surface);
    color: var(--color-primary);
    box-shadow: var(--shadow-soft);
}

.tab-content {
    display: none;
}

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

.features {
    margin-top: 1.5rem;
    text-align: left;
}

.features h3 {
    color: var(--color-text-primary);
    margin-bottom: 0.75rem;
    font-size: 1rem;
}

.features ul {
    list-style: none;
    margin: 0;
    padding: 0;
}

.features li {
    padding: 0.25rem 0;
    color: var(--color-text-secondary);
    font-size: 0.9rem;
}

/* Status Classes */
.text-center { text-align: center; }
.text-success { color: var(--color-success); }
.text-danger { color: var(--color-danger); }
.status-success { color: var(--color-success); }
.status-warning { color: var(--color-warning); }
.status-danger { color: var(--color-danger); }

/* Edit Forms */
.edit-form {
    background: var(--color-warning-bg);
    border: 1px solid rgba(230, 129, 97, 0.2);
    border-radius: 8px;
    padding: 1rem;
    margin-top: 1rem;
}

.edit-form h4 {
    color: var(--color-warning);
    margin: 0 0 1rem 0;
    font-size: 1rem;
}

/* Modal Overlay */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: 1rem;
}

.modal {
    background: var(--color-surface);
    border-radius: 12px;
    max-width: 500px;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
    padding: 1.5rem;
}

.modal h3 {
    margin: 0 0 1rem 0;
    color: var(--color-text-primary);
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .container {
        padding: 1rem 0.5rem;
    }

    .card-body {
        padding: 1rem;
    }

    table th,
    table td {
        padding: 0.5rem;
        font-size: 0.85rem;
    }

    .btn {
        padding: 0.75rem 1rem;
        font-size: 0.85rem;
    }

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

@media (max-width: 480px) {
    .nav {
        flex-direction: column;
        gap: 0.25rem;
    }

    .nav a {
        text-align: center;
        padding: 0.75rem;
    }

    .form-row {
        grid-template-columns: 1fr;
    }

    .budget-header {
        flex-direction: column;
        align-items: flex-start;
    }
}

/* Print Styles */
@media print {
    .header .nav,
    .btn,
    .form-group,
    .edit-form {
        display: none !important;
    }

    .container {
        max-width: none;
        padding: 0;
    }

    .card {
        box-shadow: none;
        border: 1px solid #ddd;
    }
}

/* Focus Styles for Accessibility */
.btn:focus,
.form-control:focus,
.nav a:focus,
.tab-btn:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

/* Loading States */
.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

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