/* Native Mobile App Design */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
    -webkit-touch-callout: none;
    -webkit-user-select: none;
    user-select: none;
}

:root {
    --primary-color: #007AFF;
    --primary-dark: #0056CC;
    --secondary-color: #5856D6;
    --success-color: #34C759;
    --danger-color: #FF3B30;
    --warning-color: #FF9500;
    
    --bg-primary: #000000;
    --bg-secondary: #1C1C1E;
    --bg-tertiary: #2C2C2E;
    --bg-card: #1C1C1E;
    --bg-modal: #2C2C2E;
    
    --text-primary: #FFFFFF;
    --text-secondary: #8E8E93;
    --text-tertiary: #636366;
    
    --border-color: #38383A;
    --separator: #38383A;
    
    --shadow-light: 0 1px 3px rgba(0, 0, 0, 0.3);
    --shadow-medium: 0 4px 12px rgba(0, 0, 0, 0.4);
    --shadow-heavy: 0 8px 25px rgba(0, 0, 0, 0.5);
    
    --radius-small: 8px;
    --radius-medium: 12px;
    --radius-large: 16px;
    --radius-xl: 20px;
    
    --status-bar-height: 44px;
    --header-height: 120px;
    --bottom-nav-height: 83px;
}

/* Global Styles */
html {
    height: 100%;
    overflow-x: hidden;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.4;
    height: 100%;
    overflow-x: hidden;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Status Bar */
.status-bar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--status-bar-height);
    background: var(--bg-primary);
    z-index: 1000;
}

/* App Container */
.app-container {
    min-height: 100vh;
    background: var(--bg-primary);
    padding-top: var(--status-bar-height);
    padding-bottom: var(--bottom-nav-height);
}

/* Header */
.app-header {
    background: var(--bg-secondary);
    padding: 16px 20px 20px;
    border-bottom: 1px solid var(--separator);
}

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

.header-left h1 {
    font-size: 28px;
    font-weight: 700;
    color: var(--text-primary);
    margin: 0;
}

.header-right {
    display: flex;
    gap: 8px;
}

.icon-btn {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-medium);
    background: var(--bg-tertiary);
    border: none;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.2s ease;
}

.icon-btn:active {
    transform: scale(0.95);
    background: var(--border-color);
}

/* Balance Card */
.balance-card {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    padding: 20px;
    border-radius: var(--radius-large);
    text-align: center;
    box-shadow: var(--shadow-medium);
}

.balance-label {
    color: rgba(255, 255, 255, 0.8);
    font-size: 14px;
    font-weight: 500;
    margin-bottom: 8px;
}

.balance-amount {
    color: white;
    font-size: 32px;
    font-weight: 700;
    letter-spacing: -0.5px;
}

/* Main Content */
.app-main {
    padding: 20px;
    flex: 1;
}

/* Stats Row */
.stats-row {
    display: flex;
    gap: 12px;
    margin-bottom: 24px;
}

.stat-card {
    flex: 1;
    background: var(--bg-card);
    padding: 16px;
    border-radius: var(--radius-medium);
    text-align: center;
    border: 1px solid var(--border-color);
}

.stat-value {
    color: var(--text-primary);
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 4px;
}

.stat-label {
    color: var(--text-secondary);
    font-size: 12px;
    font-weight: 500;
}

/* Filter Tabs */
.filter-tabs {
    display: flex;
    background: var(--bg-card);
    border-radius: var(--radius-medium);
    padding: 4px;
    margin-bottom: 20px;
    border: 1px solid var(--border-color);
}

.filter-tab {
    flex: 1;
    padding: 8px 16px;
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 14px;
    font-weight: 500;
    border-radius: var(--radius-small);
    cursor: pointer;
    transition: all 0.2s ease;
}

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

/* Expense List */
.expense-list-container {
    flex: 1;
}

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

.expense-item {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-medium);
    padding: 16px;
    transition: all 0.2s ease;
    position: relative;
}

.expense-item:active {
    transform: scale(0.98);
}

.expense-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 8px;
}

.expense-left {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.expense-amount {
    font-size: 20px;
    font-weight: 700;
    color: var(--text-primary);
}

.expense-category {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 4px 12px;
    border-radius: var(--radius-large);
    font-size: 12px;
    font-weight: 600;
    width: fit-content;
}

.expense-category.food { background: rgba(255, 149, 0, 0.2); color: #FF9500; }
.expense-category.transport { background: rgba(0, 122, 255, 0.2); color: #007AFF; }
.expense-category.shopping { background: rgba(88, 86, 214, 0.2); color: #5856D6; }
.expense-category.entertainment { background: rgba(255, 45, 85, 0.2); color: #FF2D55; }
.expense-category.bills { background: rgba(255, 59, 48, 0.2); color: #FF3B30; }
.expense-category.health { background: rgba(52, 199, 89, 0.2); color: #34C759; }
.expense-category.other { background: rgba(142, 142, 147, 0.2); color: #8E8E93; }

.expense-description {
    color: var(--text-secondary);
    font-size: 14px;
    margin-bottom: 8px;
    line-height: 1.3;
}

.expense-date {
    color: var(--text-tertiary);
    font-size: 12px;
    font-weight: 500;
}

.expense-actions {
    display: flex;
    align-items: flex-start;
    margin-left: 12px;
}

.btn-delete {
    width: 32px;
    height: 32px;
    border-radius: var(--radius-small);
    background: rgba(255, 59, 48, 0.1);
    border: none;
    color: var(--danger-color);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.2s ease;
    flex-shrink: 0;
}

.btn-delete:active {
    transform: scale(0.9);
    background: rgba(255, 59, 48, 0.2);
}

/* Floating Action Button */
.fab {
    position: fixed;
    bottom: calc(var(--bottom-nav-height) + 20px);
    right: 20px;
    width: 56px;
    height: 56px;
    border-radius: 28px;
    background: var(--primary-color);
    border: none;
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    box-shadow: var(--shadow-heavy);
    transition: all 0.3s ease;
    z-index: 100;
}

.fab:active {
    transform: scale(0.9);
}

/* Bottom Navigation */
.bottom-nav {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    height: var(--bottom-nav-height);
    background: var(--bg-secondary);
    border-top: 1px solid var(--separator);
    display: flex;
    padding: 8px 0 34px;
    z-index: 100;
}

.nav-item {
    flex: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: none;
    border: none;
    color: var(--text-tertiary);
    cursor: pointer;
    transition: all 0.2s ease;
    gap: 4px;
}

.nav-item.active {
    color: var(--primary-color);
}

.nav-item span {
    font-size: 10px;
    font-weight: 500;
}

/* Modal */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.7);
    display: none;
    align-items: flex-end;
    z-index: 1000;
    backdrop-filter: blur(10px);
}

.modal-overlay.active {
    display: flex;
}

.modal-content {
    background: var(--bg-modal);
    border-radius: var(--radius-xl) var(--radius-xl) 0 0;
    padding: 24px 20px 40px;
    width: 100%;
    max-height: 80vh;
    overflow-y: auto;
    transform: translateY(100%);
    transition: transform 0.3s ease;
}

.modal-overlay.active .modal-content {
    transform: translateY(0);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
}

.modal-header h2 {
    font-size: 20px;
    font-weight: 700;
    color: var(--text-primary);
}

.close-btn {
    width: 32px;
    height: 32px;
    border-radius: var(--radius-small);
    background: var(--bg-tertiary);
    border: none;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
}

/* Form Styles */
.expense-form .form-group {
    margin-bottom: 20px;
}

.expense-form label {
    display: block;
    color: var(--text-primary);
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 8px;
}

.amount-input {
    position: relative;
    display: flex;
    align-items: center;
}

.currency {
    position: absolute;
    left: 16px;
    color: var(--text-secondary);
    font-size: 18px;
    font-weight: 600;
    z-index: 1;
}

.amount-input input {
    width: 100%;
    padding: 16px 16px 16px 40px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-medium);
    color: var(--text-primary);
    font-size: 18px;
    font-weight: 600;
}

.amount-input input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.category-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 12px;
}

.category-btn {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 16px 8px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-medium);
    cursor: pointer;
    transition: all 0.2s ease;
    gap: 8px;
}

.category-btn.selected {
    background: var(--primary-color);
    border-color: var(--primary-color);
    color: white;
}

.category-btn:active {
    transform: scale(0.95);
}

.category-icon {
    font-size: 24px;
}

.category-btn span:last-child {
    font-size: 12px;
    font-weight: 500;
    color: var(--text-primary);
}

.category-btn.selected span:last-child {
    color: white;
}

.expense-form input[type="text"],
.expense-form input[type="datetime-local"] {
    width: 100%;
    padding: 16px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-medium);
    color: var(--text-primary);
    font-size: 16px;
}

.expense-form input:focus {
    outline: none;
    border-color: var(--primary-color);
}

.btn-primary {
    width: 100%;
    padding: 16px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--radius-medium);
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    margin-top: 8px;
    transition: all 0.2s ease;
}

.btn-primary:active {
    transform: scale(0.98);
    background: var(--primary-dark);
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 40px 20px;
    color: var(--text-secondary);
}

.empty-state-icon {
    width: 64px;
    height: 64px;
    margin: 0 auto 16px;
    opacity: 0.5;
}

.empty-state h3 {
    font-size: 18px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.empty-state p {
    font-size: 14px;
    color: var(--text-secondary);
}

/* Animations */
@keyframes slideUp {
    from {
        transform: translateY(100%);
    }
    to {
        transform: translateY(0);
    }
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

/* Page Content */
.page-content {
    width: 100%;
}

/* Stats Page */
.stats-header {
    margin-bottom: 20px;
}

.stats-header h2 {
    font-size: 24px;
    font-weight: 700;
    color: var(--text-primary);
}

.chart-container {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-medium);
    padding: 20px;
    margin-bottom: 20px;
    text-align: center;
}

.category-stats {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.category-stat-item {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-medium);
    padding: 16px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.category-stat-left {
    display: flex;
    align-items: center;
    gap: 12px;
}

.category-stat-icon {
    font-size: 24px;
}

.category-stat-name {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-primary);
}

.category-stat-amount {
    font-size: 16px;
    font-weight: 700;
    color: var(--primary-color);
}

/* Categories Page */
.categories-header {
    margin-bottom: 20px;
}

.categories-header h2 {
    font-size: 24px;
    font-weight: 700;
    color: var(--text-primary);
}

.category-list {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
}

.category-list-item {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-medium);
    padding: 20px;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s ease;
}

.category-list-item:active {
    transform: scale(0.95);
}

.category-list-icon {
    font-size: 32px;
    margin-bottom: 8px;
}

.category-list-name {
    font-size: 14px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.category-list-count {
    font-size: 12px;
    color: var(--text-secondary);
}

/* Settings Modal */
.settings-content {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.setting-group {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.setting-group label {
    font-size: 16px;
    font-weight: 600;
    color: var(--text-primary);
}

.setting-group select {
    width: 100%;
    padding: 16px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-medium);
    color: var(--text-primary);
    font-size: 16px;
}

.toggle-group, .radio-group {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.toggle-label, .radio-label {
    display: flex;
    align-items: center;
    gap: 12px;
    cursor: pointer;
    font-size: 14px;
    color: var(--text-primary);
}

.toggle-slider {
    width: 44px;
    height: 24px;
    background: var(--bg-tertiary);
    border-radius: 12px;
    position: relative;
    transition: background 0.2s ease;
}

.toggle-slider::after {
    content: '';
    position: absolute;
    top: 2px;
    left: 2px;
    width: 20px;
    height: 20px;
    background: white;
    border-radius: 50%;
    transition: transform 0.2s ease;
}

input[type="checkbox"]:checked + .toggle-slider {
    background: var(--primary-color);
}

input[type="checkbox"]:checked + .toggle-slider::after {
    transform: translateX(20px);
}

.radio-button {
    width: 20px;
    height: 20px;
    border: 2px solid var(--border-color);
    border-radius: 50%;
    position: relative;
    transition: border-color 0.2s ease;
}

.radio-button::after {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 10px;
    height: 10px;
    background: var(--primary-color);
    border-radius: 50%;
    transform: translate(-50%, -50%) scale(0);
    transition: transform 0.2s ease;
}

input[type="radio"]:checked + .radio-button {
    border-color: var(--primary-color);
}

input[type="radio"]:checked + .radio-button::after {
    transform: translate(-50%, -50%) scale(1);
}

input[type="checkbox"], input[type="radio"] {
    display: none;
}

.setting-description {
    margin-top: 8px;
}

.setting-description p {
    font-size: 12px;
    color: var(--text-secondary);
    margin: 0;
    line-height: 1.4;
}

/* Authentication Screen */
.auth-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--bg-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
}

.auth-container {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-large);
    padding: 40px 30px;
    text-align: center;
    max-width: 320px;
    width: 100%;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.3);
}

.auth-header {
    margin-bottom: 32px;
}

.auth-logo {
    font-size: 48px;
    margin-bottom: 16px;
}

.auth-header h2 {
    font-size: 24px;
    font-weight: 700;
    color: var(--text-primary);
    margin: 0 0 8px 0;
}

.auth-header p {
    font-size: 16px;
    color: var(--text-secondary);
    margin: 0;
    line-height: 1.4;
}

.auth-content {
    display: flex;
    flex-direction: column;
    gap: 16px;
    margin-bottom: 24px;
}

.auth-btn-primary {
    width: 100%;
    padding: 16px 20px;
    background: var(--primary-color);
    color: white;
    border: none;
    border-radius: var(--radius-medium);
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
}

.auth-btn-primary:active {
    transform: scale(0.98);
    background: #0056CC;
}

.auth-btn-secondary {
    width: 100%;
    padding: 12px 20px;
    background: transparent;
    color: var(--text-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-medium);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
}

.auth-btn-secondary:active {
    transform: scale(0.98);
    background: var(--bg-tertiary);
}

.auth-footer {
    border-top: 1px solid var(--border-color);
    padding-top: 20px;
}

.auth-footer p {
    font-size: 12px;
    color: var(--text-tertiary);
    margin: 0;
    line-height: 1.4;
}

/* DateTime Container */
.datetime-container {
    display: flex;
    gap: 8px;
    align-items: center;
}

.datetime-container input {
    flex: 1;
}

.advanced-date-btn {
    width: 48px;
    height: 48px;
    background: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-medium);
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.2s ease;
}

.advanced-date-btn:active {
    transform: scale(0.95);
    background: var(--border-color);
}

.datetime-note {
    font-size: 12px;
    color: var(--text-secondary);
    font-style: italic;
}

/* Safe Area Support */
@supports (padding-bottom: env(safe-area-inset-bottom)) {
    .bottom-nav {
        padding-bottom: calc(34px + env(safe-area-inset-bottom));
    }
    
    .fab {
        bottom: calc(var(--bottom-nav-height) + 20px + env(safe-area-inset-bottom));
    }
    
    .modal-content {
        padding-bottom: calc(40px + env(safe-area-inset-bottom));
    }
}