/* ========================================
   Room Rental Receipt Application
   Clean & Modern Vietnamese UI
======================================== */

:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary: #64748b;
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
    --bg: #f1f5f9;
    --card-bg: #ffffff;
    --text: #1e293b;
    --text-light: #64748b;
    --border: #e2e8f0;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --radius: 12px;
}

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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 20px;
}

/* Header */
header {
    text-align: center;
    padding: 30px 0;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
    border-radius: var(--radius);
    margin-bottom: 24px;
    box-shadow: var(--shadow);
}

header h1 {
    font-size: 2rem;
    font-weight: 700;
    margin-bottom: 8px;
}

header .subtitle {
    opacity: 0.9;
    font-size: 1.1rem;
}

/* Cards */
.card {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 24px;
    margin-bottom: 24px;
    box-shadow: var(--shadow);
}

.card h2 {
    font-size: 1.25rem;
    color: var(--text);
    margin-bottom: 16px;
    padding-bottom: 12px;
    border-bottom: 2px solid var(--border);
}

/* Unit Prices Grid */
.price-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 16px;
    margin-bottom: 16px;
}

.price-item {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.price-item label {
    font-weight: 500;
    color: var(--text-light);
    font-size: 0.9rem;
}

.price-item input {
    padding: 10px 14px;
    border: 2px solid var(--border);
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.2s;
}

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

/* Receipt Settings */
.settings-grid {
    display: flex;
    gap: 24px;
    flex-wrap: wrap;
}

.setting-item {
    display: flex;
    align-items: center;
    gap: 12px;
}

.setting-item label {
    font-weight: 500;
    color: var(--text-light);
}

.setting-item input,
.setting-item select {
    padding: 10px 14px;
    border: 2px solid var(--border);
    border-radius: 8px;
    font-size: 1rem;
    min-width: 150px;
}

.setting-item input:focus,
.setting-item select:focus {
    outline: none;
    border-color: var(--primary);
}

/* Buttons */
.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
}

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

.btn-secondary:hover {
    background: #475569;
}

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

.btn-success:hover {
    background: #059669;
}

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

.btn-danger:hover {
    background: #dc2626;
}

.btn-small {
    padding: 6px 12px;
    font-size: 0.85rem;
}

.btn-group {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
}

/* Table */
.table-container {
    overflow-x: auto;
    margin-bottom: 12px;
}

table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.9rem;
}

thead {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
}

th {
    padding: 14px 12px;
    text-align: left;
    font-weight: 600;
    white-space: nowrap;
}

td {
    padding: 12px;
    border-bottom: 1px solid var(--border);
    vertical-align: middle;
}

tbody tr:hover {
    background: #f8fafc;
}

tbody tr:nth-child(even) {
    background: #fafafa;
}

tbody tr:nth-child(even):hover {
    background: #f1f5f9;
}

td[contenteditable="true"] {
    cursor: text;
    min-width: 80px;
}

td[contenteditable="true"]:focus {
    outline: 2px solid var(--primary);
    background: #eff6ff;
}

.table-note {
    font-size: 0.85rem;
    color: var(--text-light);
    font-style: italic;
}

.action-btns {
    display: flex;
    gap: 6px;
    flex-wrap: nowrap;
}

.total-cell {
    font-weight: 700;
    color: var(--primary);
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
}

.modal-content {
    background: var(--card-bg);
    margin: 5% auto;
    padding: 30px;
    border-radius: var(--radius);
    width: 90%;
    max-width: 700px;
    max-height: 85vh;
    overflow-y: auto;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.25);
    animation: slideIn 0.3s ease;
}

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

.close {
    float: right;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
    color: var(--text-light);
    transition: color 0.2s;
}

.close:hover {
    color: var(--danger);
}

.modal-content h2 {
    margin-bottom: 24px;
    color: var(--text);
}

/* Form */
.form-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
    margin-bottom: 24px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.form-group.full-width {
    grid-column: 1 / -1;
}

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

.form-group input,
.form-group textarea,
.form-group select {
    padding: 12px 14px;
    border: 2px solid var(--border);
    border-radius: 8px;
    font-size: 1rem;
    transition: border-color 0.2s;
}

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

.form-group input[readonly] {
    background: #f1f5f9;
    color: var(--text-light);
}

.form-group small {
    font-size: 0.8rem;
    color: var(--text-light);
}

.form-actions {
    display: flex;
    gap: 12px;
    justify-content: flex-end;
}

/* Footer */
footer {
    text-align: center;
    padding: 20px;
    color: var(--text-light);
    font-size: 0.9rem;
}

/* Responsive */
@media (max-width: 768px) {
    .container {
        padding: 12px;
    }

    header h1 {
        font-size: 1.5rem;
    }

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

    .card {
        padding: 16px;
    }

    .btn {
        padding: 10px 16px;
        font-size: 0.9rem;
    }

    .settings-grid {
        flex-direction: column;
        gap: 12px;
    }

    .setting-item {
        flex-direction: column;
        align-items: flex-start;
    }
}

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

.empty-state p {
    font-size: 1.1rem;
    margin-bottom: 16px;
}

/* Utility classes */
.text-right {
    text-align: right;
}

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

.font-bold {
    font-weight: 700;
}

/* Number formatting */
.currency {
    font-family: 'Consolas', 'Monaco', monospace;
    font-weight: 600;
}