/* ========================================
   Expense Tracker - Dark Mode & Glassmorphism
   ======================================== */

:root {
    --bg-primary: #0d1117;
    --bg-secondary: #161b22;
    --bg-tertiary: #21262d;
    --accent: #58a6ff;
    --accent-hover: #79b8ff;
    --text-primary: #f0f6fc;
    --text-secondary: #8b949e;
    --glass-bg: rgba(22, 27, 34, 0.7);
    --glass-border: rgba(240, 246, 252, 0.1);
    --glass-shadow: rgba(0, 0, 0, 0.3);
    --income-color: #3fb950;
    --income-bg: rgba(63, 185, 80, 0.12);
    --expense-color: #f85149;
    --expense-bg: rgba(248, 81, 73, 0.12);
    --balance-positive: #3fb950;
    --balance-negative: #f85149;
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    line-height: 1.5;
    background-image: 
        radial-gradient(ellipse at 20% 20%, rgba(88, 166, 255, 0.08) 0%, transparent 50%),
        radial-gradient(ellipse at 80% 80%, rgba(63, 185, 80, 0.05) 0%, transparent 50%),
        radial-gradient(ellipse at 50% 50%, rgba(248, 81, 73, 0.03) 0%, transparent 70%);
}

/* Glassmorphism Container */
.app-container {
    max-width: 480px;
    margin: 0 auto;
    padding: 1.5rem;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Glass Card Base */
.glass-card {
    background: var(--glass-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-md);
    box-shadow: 0 8px 32px var(--glass-shadow);
}

/* Header */
.app-header {
    text-align: center;
    margin-bottom: 2rem;
}

.app-header h1 {
    font-size: 1.75rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 0.25rem;
}

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

/* Balance Overview */
.balance-overview {
    margin-bottom: 1.5rem;
}

.balance-card {
    padding: 1.25rem 1.5rem;
    border-radius: var(--radius-md);
    margin-bottom: 0.75rem;
}

.balance-card.total-balance {
    background: var(--glass-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    box-shadow: 0 8px 32px var(--glass-shadow);
}

.balance-card .label {
    display: block;
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 0.35rem;
}

.balance-card .value {
    font-size: 1.75rem;
    font-weight: 700;
}

.balance-card.total-balance .value {
    color: var(--text-primary);
}

.balance-card.total-balance.positive .value {
    color: var(--balance-positive);
}

.balance-card.total-balance.negative .value {
    color: var(--balance-negative);
}

.balance-cards-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 0.75rem;
}

.balance-card.income {
    background: var(--income-bg);
    border: 1px solid rgba(63, 185, 80, 0.3);
    color: var(--income-color);
}

.balance-card.expense {
    background: var(--expense-bg);
    border: 1px solid rgba(248, 81, 73, 0.3);
    color: var(--expense-color);
}

/* Add Transaction Form */
.add-transaction {
    margin-bottom: 1.5rem;
    padding: 1.5rem;
    background: var(--glass-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-md);
    box-shadow: 0 8px 32px var(--glass-shadow);
}

.add-transaction h2,
.transaction-history h2 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: var(--text-primary);
}

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

.form-group label {
    display: block;
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 0.4rem;
}

.form-group input {
    width: 100%;
    padding: 0.75rem 1rem;
    font-size: 1rem;
    color: var(--text-primary);
    background: var(--bg-tertiary);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-sm);
    transition: border-color 0.2s, box-shadow 0.2s;
}

.form-group input::placeholder {
    color: var(--text-secondary);
    opacity: 0.7;
}

.form-group input:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px rgba(88, 166, 255, 0.2);
}

.btn-add {
    width: 100%;
    padding: 0.875rem 1.5rem;
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    background: var(--accent);
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: background 0.2s, transform 0.1s;
}

.btn-add:hover {
    background: var(--accent-hover);
}

.btn-add:active {
    transform: scale(0.98);
}

/* Transaction History */
.transaction-history {
    flex: 1;
}

.transaction-list {
    list-style: none;
}

.transaction-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1rem 1.25rem;
    margin-bottom: 0.5rem;
    background: var(--glass-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-sm);
    border-left: 4px solid transparent;
    transition: transform 0.15s, box-shadow 0.15s;
}

.transaction-item:hover {
    box-shadow: 0 4px 16px var(--glass-shadow);
}

.transaction-item.income {
    border-left-color: var(--income-color);
}

.transaction-item.expense {
    border-left-color: var(--expense-color);
}

.transaction-content {
    flex: 1;
    min-width: 0;
}

.transaction-text {
    font-size: 0.95rem;
    color: var(--text-primary);
    margin-bottom: 0.2rem;
}

.transaction-amount {
    font-size: 1.1rem;
    font-weight: 600;
}

.transaction-item.income .transaction-amount {
    color: var(--income-color);
}

.transaction-item.expense .transaction-amount {
    color: var(--expense-color);
}

.btn-delete {
    flex-shrink: 0;
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: transparent;
    border: 1px solid var(--glass-border);
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    cursor: pointer;
    font-size: 1.25rem;
    line-height: 1;
    transition: color 0.2s, background 0.2s, border-color 0.2s;
    margin-left: 0.75rem;
}

.btn-delete:hover {
    color: var(--expense-color);
    background: var(--expense-bg);
    border-color: rgba(248, 81, 73, 0.3);
}

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

/* Empty State */
.transaction-list:empty::after {
    content: 'Nema transakcija. Dodajte prvu!';
    display: block;
    padding: 2rem;
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.95rem;
}

/* Responsive */
@media (max-width: 520px) {
    .app-container {
        padding: 1rem;
    }

    .app-header h1 {
        font-size: 1.5rem;
    }

    .balance-card .value {
        font-size: 1.5rem;
    }

    .balance-cards-row {
        gap: 0.5rem;
    }

    .balance-card {
        padding: 1rem 1.25rem;
    }
}