/* ===== CSS Reset & Variables ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    /* Color Palette */
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --secondary-gradient: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    --success-gradient: linear-gradient(135deg, #43e97b 0%, #38f9d7 100%);
    --warning-gradient: linear-gradient(135deg, #fa709a 0%, #fee140 100%);
    
    --bg-primary: #0a0e27;
    --bg-secondary: #151b3d;
    --bg-card: rgba(255, 255, 255, 0.05);
    --bg-card-hover: rgba(255, 255, 255, 0.08);
    
    --text-primary: #ffffff;
    --text-secondary: #b8c1ec;
    --text-muted: #7c8db5;
    
    --border-color: rgba(255, 255, 255, 0.1);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
    
    /* Typography */
    --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-heading: 'Outfit', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    
    /* Border Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    
    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
    --transition-slow: 0.5s ease;
}

/* ===== Base Styles ===== */
body {
    font-family: var(--font-body);
    background: var(--bg-primary);
    background-image: 
        radial-gradient(at 0% 0%, rgba(102, 126, 234, 0.15) 0px, transparent 50%),
        radial-gradient(at 100% 100%, rgba(118, 75, 162, 0.15) 0px, transparent 50%);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    padding: var(--spacing-lg) var(--spacing-sm);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
}

/* ===== Typography ===== */
.main-title {
    font-family: var(--font-heading);
    font-size: 3rem;
    font-weight: 800;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    text-align: center;
    margin-bottom: var(--spacing-xs);
    animation: fadeInUp 0.6s ease;
}

.subtitle {
    text-align: center;
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: var(--spacing-xl);
    animation: fadeInUp 0.6s ease 0.1s backwards;
}

.section-title {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

/* ===== Card Component ===== */
.card {
    background: var(--bg-card);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-normal);
    animation: fadeInUp 0.6s ease;
}

.card:hover {
    background: var(--bg-card-hover);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

/* ===== Budget Setup ===== */
.budget-setup {
    margin-bottom: var(--spacing-lg);
    animation-delay: 0.2s;
}

.setup-form {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
    align-items: end;
}

/* ===== Form Elements ===== */
.form-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.form-group label {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

input[type="text"],
input[type="number"],
input[type="date"],
select {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    padding: 0.75rem 1rem;
    color: var(--text-primary);
    font-family: var(--font-body);
    font-size: 1rem;
    transition: all var(--transition-fast);
}

input:focus,
select:focus {
    outline: none;
    border-color: #667eea;
    background: rgba(102, 126, 234, 0.1);
    box-shadow: 0 0 0 3px rgba(102, 126, 234, 0.2);
}

input::placeholder {
    color: var(--text-muted);
}

/* ===== Buttons ===== */
.btn {
    padding: 0.875rem 2rem;
    border: none;
    border-radius: var(--radius-md);
    font-family: var(--font-body);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-normal);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.2);
    transform: translate(-50%, -50%);
    transition: width 0.6s, height 0.6s;
}

.btn:hover::before {
    width: 300px;
    height: 300px;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(102, 126, 234, 0.4);
}

.btn-add {
    background: var(--success-gradient);
    color: white;
    width: 100%;
    margin-top: var(--spacing-sm);
}

.btn-add:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(67, 233, 123, 0.4);
}

.btn-delete {
    background: var(--secondary-gradient);
    color: white;
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

.btn-delete:hover {
    transform: scale(1.05);
    box-shadow: 0 4px 12px rgba(245, 87, 108, 0.4);
}

/* ===== Dashboard Stats ===== */
.dashboard {
    margin-bottom: var(--spacing-lg);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.stat-card {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    padding: var(--spacing-md);
    animation-delay: 0.3s;
}

.stat-card.highlight {
    background: linear-gradient(135deg, rgba(102, 126, 234, 0.15) 0%, rgba(118, 75, 162, 0.15) 100%);
    border: 1px solid rgba(102, 126, 234, 0.3);
}

.stat-icon {
    font-size: 2.5rem;
    animation: float 3s ease-in-out infinite;
}

.stat-content {
    flex: 1;
}

.stat-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 0.25rem;
}

.stat-value {
    font-family: var(--font-heading);
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-primary);
}

/* ===== Progress Bar ===== */
.progress-container {
    animation-delay: 0.4s;
}

.progress-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: var(--spacing-sm);
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--text-secondary);
}

.progress-bar {
    height: 20px;
    background: rgba(255, 255, 255, 0.05);
    border-radius: var(--radius-xl);
    overflow: hidden;
    position: relative;
}

.progress-fill {
    height: 100%;
    background: var(--primary-gradient);
    border-radius: var(--radius-xl);
    transition: width 0.6s ease;
    position: relative;
    overflow: hidden;
}

.progress-fill::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    bottom: 0;
    right: 0;
    background: linear-gradient(
        90deg,
        transparent,
        rgba(255, 255, 255, 0.3),
        transparent
    );
    animation: shimmer 2s infinite;
}

/* ===== Add Expense Form ===== */
.add-expense {
    margin-bottom: var(--spacing-lg);
    animation-delay: 0.5s;
}

.expense-form {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-md);
}

/* ===== Category Summary ===== */
.category-summary {
    margin-bottom: var(--spacing-lg);
}

.category-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: var(--spacing-md);
}

.category-card {
    background: var(--bg-card);
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: var(--spacing-md);
    transition: all var(--transition-normal);
    animation: fadeInScale 0.4s ease;
}

.category-card:hover {
    transform: translateY(-4px) scale(1.02);
    box-shadow: var(--shadow-lg);
}

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

.category-icon {
    font-size: 1.5rem;
}

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

.category-amount {
    font-family: var(--font-heading);
    font-size: 1.5rem;
    font-weight: 700;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
}

.category-count {
    font-size: 0.875rem;
    color: var(--text-muted);
}

/* ===== Expense List ===== */
.expense-list {
    margin-bottom: var(--spacing-lg);
}

.list-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.filters {
    display: flex;
    gap: var(--spacing-sm);
    flex-wrap: wrap;
}

.filter-select {
    min-width: 150px;
}

.expense-table-container {
    overflow-x: auto;
    animation-delay: 0.6s;
}

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

.expense-table thead {
    background: rgba(102, 126, 234, 0.1);
}

.expense-table th {
    padding: var(--spacing-md);
    text-align: left;
    font-weight: 600;
    color: var(--text-secondary);
    text-transform: uppercase;
    font-size: 0.875rem;
    letter-spacing: 0.5px;
    border-bottom: 2px solid var(--border-color);
}

.expense-table td {
    padding: var(--spacing-md);
    border-bottom: 1px solid var(--border-color);
    color: var(--text-primary);
}

.expense-table tbody tr {
    transition: all var(--transition-fast);
    animation: fadeInLeft 0.4s ease;
}

.expense-table tbody tr:hover {
    background: rgba(102, 126, 234, 0.05);
}

.category-badge {
    display: inline-block;
    padding: 0.375rem 0.75rem;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 600;
    background: rgba(102, 126, 234, 0.2);
    color: var(--text-primary);
}

.empty-state {
    text-align: center;
}

.empty-message {
    padding: var(--spacing-xl) var(--spacing-md);
}

.empty-message p {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xs);
}

.empty-subtitle {
    font-size: 0.875rem;
    color: var(--text-muted);
}

/* ===== Animations ===== */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInScale {
    from {
        opacity: 0;
        transform: scale(0.9);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

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

@keyframes float {
    0%, 100% {
        transform: translateY(0);
    }
    50% {
        transform: translateY(-10px);
    }
}

@keyframes shimmer {
    0% {
        transform: translateX(-100%);
    }
    100% {
        transform: translateX(100%);
    }
}

/* ===== Responsive Design ===== */
@media (max-width: 768px) {
    .main-title {
        font-size: 2rem;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .setup-form {
        grid-template-columns: 1fr;
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .list-header {
        flex-direction: column;
        align-items: flex-start;
    }
    
    .filters {
        width: 100%;
    }
    
    .filter-select {
        flex: 1;
        min-width: auto;
    }
    
    .expense-table {
        font-size: 0.875rem;
    }
    
    .expense-table th,
    .expense-table td {
        padding: var(--spacing-sm);
    }
}

@media (max-width: 480px) {
    body {
        padding: var(--spacing-sm);
    }
    
    .card {
        padding: var(--spacing-md);
    }
    
    .stat-value {
        font-size: 1.5rem;
    }
}