@import url('https://fonts.googleapis.com/css2?family=Prompt:wght@300;400;500;600;700&family=Sarabun:ital,wght@0,300;0,400;0,500;0,600;0,700;1,400&display=swap');

:root {
    --bg-primary: #f8fafc;
    --bg-card: #ffffff;
    --text-main: #1e293b;
    --text-muted: #64748b;
    --primary: #1e3a8a;
    --primary-light: #3b82f6;
    --primary-hover: #172554;
    --accent: #0f766e;
    --success: #10b981;
    --success-light: #ecfdf5;
    --danger: #ef4444;
    --danger-light: #fef2f2;
    --warning: #f59e0b;
    --border-color: #e2e8f0;
    --radius-lg: 16px;
    --radius-md: 10px;
    --radius-sm: 6px;
    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
    --font-sans: 'Prompt', 'Sarabun', sans-serif;
}

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

body {
    background-color: var(--bg-primary);
    color: var(--text-main);
    font-family: var(--font-sans);
    line-height: 1.6;
    padding: 0;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

header {
    background: linear-gradient(135deg, var(--primary), var(--primary-light));
    color: #ffffff;
    padding: 2.5rem 1rem;
    text-align: center;
    box-shadow: var(--shadow-md);
    position: relative;
    overflow: hidden;
}

header::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255,255,255,0.08) 0%, transparent 60%);
    pointer-events: none;
}

header h1 {
    font-size: 2.2rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    letter-spacing: 0.5px;
}

header p {
    font-size: 1.1rem;
    font-weight: 300;
    opacity: 0.9;
}

main {
    flex: 1;
    max-width: 900px;
    width: 100%;
    margin: 2rem auto;
    padding: 0 1.5rem;
}

/* Page Container (Forms / Cards) */
.content-box {
    background-color: var(--bg-card);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-md);
    padding: 2.5rem;
    border: 1px solid var(--border-color);
    margin-bottom: 2rem;
}

.section-title {
    font-size: 1.4rem;
    font-weight: 600;
    color: var(--primary);
    margin-bottom: 1.5rem;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    border-bottom: 2px solid var(--bg-primary);
    padding-bottom: 0.75rem;
}

/* Form Styling */
.form-group {
    margin-bottom: 1.5rem;
}

.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1.25rem;
    margin-bottom: 1.5rem;
}

label {
    display: block;
    font-weight: 500;
    margin-bottom: 0.5rem;
    color: var(--text-main);
    font-size: 0.95rem;
}

input[type="text"],
input[type="number"],
input[type="datetime-local"],
select {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 1.5px solid var(--border-color);
    border-radius: var(--radius-md);
    font-family: var(--font-sans);
    font-size: 1rem;
    color: var(--text-main);
    transition: all 0.2s ease;
    background-color: #ffffff;
}

input[type="text"]:focus,
input[type="number"]:focus,
input[type="datetime-local"]:focus,
select:focus {
    outline: none;
    border-color: var(--primary-light);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.15);
}

select {
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' fill='none' viewBox='0 0 24 24' stroke='%23475569' stroke-width='2'%3E%3Cpath stroke-linecap='round' stroke-linejoin='round' d='M19.5 8.25l-7.5 7.5-7.5-7.5'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 1rem center;
    background-size: 1.25rem;
    padding-right: 2.5rem;
}

/* Notification & Alerts */
.alert {
    padding: 1rem 1.25rem;
    border-radius: var(--radius-md);
    font-size: 0.95rem;
    margin-bottom: 1.5rem;
    display: none;
    align-items: center;
    gap: 0.75rem;
    animation: fadeIn 0.3s ease;
}

.alert-danger {
    display: flex;
    background-color: var(--danger-light);
    color: var(--danger);
    border: 1px solid rgba(239, 68, 68, 0.2);
}

.alert-success {
    display: flex;
    background-color: var(--success-light);
    color: var(--success);
    border: 1px solid rgba(16, 185, 129, 0.2);
}

/* Club Selection Cards Grid */
.club-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 1rem;
    margin-top: 1rem;
    max-height: 400px;
    overflow-y: auto;
    padding: 0.5rem;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    background-color: var(--bg-primary);
}

.club-card {
    background-color: var(--bg-card);
    border: 1.5px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 1rem;
    cursor: pointer;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.club-card:hover:not(.disabled) {
    transform: translateY(-2px);
    border-color: var(--primary-light);
    box-shadow: var(--shadow-sm);
}

.club-card.selected {
    border-color: var(--primary);
    background-color: rgba(59, 130, 246, 0.05);
    box-shadow: 0 0 0 2px var(--primary);
}

.club-card.disabled {
    opacity: 0.6;
    background-color: #f1f5f9;
    border-color: #cbd5e1;
    cursor: not-allowed;
}

.club-name {
    font-weight: 600;
    font-size: 1.05rem;
    margin-bottom: 0.25rem;
}

.club-teacher {
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 0.75rem;
}

.club-seats {
    font-size: 0.85rem;
    font-weight: 500;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.badge {
    padding: 0.2rem 0.5rem;
    border-radius: 9999px;
    font-size: 0.75rem;
    font-weight: 600;
}

.badge-primary {
    background-color: #dbeafe;
    color: var(--primary-light);
}

.badge-danger {
    background-color: var(--danger-light);
    color: var(--danger);
}

.badge-warning {
    background-color: #fef3c7;
    color: #d97706;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem 1.5rem;
    font-family: var(--font-sans);
    font-size: 1rem;
    font-weight: 500;
    border-radius: var(--radius-md);
    border: none;
    cursor: pointer;
    transition: all 0.2s ease;
    gap: 0.5rem;
    text-decoration: none;
}

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

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

.btn-secondary {
    background-color: #e2e8f0;
    color: var(--text-main);
}

.btn-secondary:hover {
    background-color: #cbd5e1;
}

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

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

.btn-block {
    width: 100%;
}

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

/* Success Receipt Layout */
.receipt {
    border: 2px dashed var(--border-color);
    padding: 2rem;
    border-radius: var(--radius-md);
    background-color: #fafafa;
    margin: 1.5rem 0;
    font-size: 1.05rem;
}

.receipt-row {
    display: flex;
    justify-content: space-between;
    padding: 0.75rem 0;
    border-bottom: 1px solid #f1f5f9;
}

.receipt-row:last-child {
    border-bottom: none;
}

.receipt-label {
    color: var(--text-muted);
}

.receipt-value {
    font-weight: 600;
}

/* Admin Dashboard Layout */
.admin-navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 1rem;
}

.admin-tabs {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
    background-color: #f1f5f9;
    padding: 0.35rem;
    border-radius: var(--radius-md);
}

.tab-btn {
    flex: 1;
    padding: 0.6rem 1rem;
    font-family: var(--font-sans);
    font-weight: 500;
    border: none;
    border-radius: var(--radius-sm);
    cursor: pointer;
    background-color: transparent;
    color: var(--text-muted);
    transition: all 0.15s ease;
}

.tab-btn.active {
    background-color: #ffffff;
    color: var(--primary);
    box-shadow: var(--shadow-sm);
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

/* Admin Table */
.table-container {
    overflow-x: auto;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    margin-bottom: 1.5rem;
}

table {
    width: 100%;
    border-collapse: collapse;
    text-align: left;
}

th, td {
    padding: 0.85rem 1.25rem;
    border-bottom: 1px solid var(--border-color);
    font-size: 0.95rem;
}

th {
    background-color: #f1f5f9;
    font-weight: 600;
    color: var(--text-main);
}

tr:hover {
    background-color: #f8fafc;
}

/* Admin Controls & Filters */
.controls-row {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
}

.search-input {
    max-width: 300px;
    width: 100%;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 1.25rem;
    margin-bottom: 2rem;
}

.stat-card {
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 1.25rem;
    box-shadow: var(--shadow-sm);
    text-align: center;
}

.stat-value {
    font-size: 1.8rem;
    font-weight: 700;
    color: var(--primary);
}

.stat-label {
    font-size: 0.85rem;
    color: var(--text-muted);
}

/* Login Card */
.login-card {
    max-width: 400px;
    width: 100%;
    margin: 4rem auto;
}

/* Modal for Edit / Add Club */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(15, 23, 42, 0.4);
    backdrop-filter: blur(4px);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 1000;
}

.modal-content {
    background-color: var(--bg-card);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-lg);
    width: 95%;
    max-width: 500px;
    padding: 2rem;
    animation: slideUp 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.75rem;
}

.modal-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--primary);
}

.modal-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-muted);
}

.modal-footer {
    display: flex;
    justify-content: flex-end;
    gap: 0.75rem;
    margin-top: 1.5rem;
    border-top: 1px solid var(--border-color);
    padding-top: 1rem;
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(5px); }
    to { opacity: 1; transform: translateY(0); }
}

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

/* Footer Styling */
footer {
    text-align: center;
    padding: 1.5rem 1rem;
    font-size: 0.85rem;
    color: var(--text-muted);
    border-top: 1px solid var(--border-color);
    background-color: #ffffff;
    margin-top: auto;
}

/* Utilities */
.text-center { text-align: center; }
.mt-4 { margin-top: 1rem; }
.mr-2 { margin-right: 0.5rem; }
.flex { display: flex; }
.justify-between { justify-content: space-between; }
.align-center { align-items: center; }
.gap-2 { gap: 0.5rem; }

@media (max-width: 600px) {
    header h1 {
        font-size: 1.75rem;
    }
    .content-box {
        padding: 1.5rem;
    }
    .form-row {
        grid-template-columns: 1fr;
        gap: 1rem;
    }
    .controls-row {
        flex-direction: column;
        align-items: stretch;
    }
    .search-input {
        max-width: none;
    }
}