:root {
    --primary: #4f46e5;
    --primary-hover: #4338ca;
    --secondary: #06b6d4;
    --background: #f8fafc;
    --card-bg: #ffffff;
    --text-main: #0f172a;
    --text-muted: #64748b;
    --border: #e2e8f0;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.05), 0 4px 6px -4px rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 8px 10px -6px rgba(0, 0, 0, 0.1);
    --radius: 12px;
}

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

body {
    font-family: 'Outfit', 'Sarabun', sans-serif;
    background-color: var(--background);
    color: var(--text-main);
    line-height: 1.6;
    padding-bottom: 3rem;
}

/* Header */
.app-header {
    background: linear-gradient(135deg, #1e1b4b 0%, #312e81 100%);
    color: white;
    padding: 1.5rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: var(--shadow);
}

.logo-area {
    display: flex;
    align-items: center;
    gap: 1rem;
}

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

.logo-area h1 {
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: -0.025em;
    background: linear-gradient(to right, #38bdf8, #818cf8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.logo-area p {
    font-size: 0.85rem;
    color: #c7d2fe;
}

.role-selector-container {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    background: rgba(255, 255, 255, 0.1);
    padding: 0.5rem 1rem;
    border-radius: 9999px;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.role-selector-container label {
    font-size: 0.875rem;
    font-weight: 500;
    color: #e0e7ff;
}

.role-select {
    background: transparent;
    border: none;
    color: white;
    font-family: inherit;
    font-size: 0.875rem;
    font-weight: 600;
    outline: none;
    cursor: pointer;
}

.role-select option {
    color: var(--text-main);
    background: white;
}

/* Container */
.app-container {
    max-width: 1200px;
    margin: 2rem auto;
    padding: 0 1.5rem;
}

/* Role Views Toggle */
.role-view {
    display: none;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.role-view.active {
    display: block;
    opacity: 1;
    animation: fadeIn 0.4s ease-out forwards;
}

.view-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
}

.view-header h2 {
    font-size: 1.5rem;
    font-weight: 700;
    color: #1e293b;
    position: relative;
}

.view-header h2::after {
    content: '';
    position: absolute;
    bottom: -6px;
    left: 0;
    width: 40px;
    height: 4px;
    background: var(--primary);
    border-radius: 9999px;
}

/* KPI Grid */
.kpi-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.kpi-card {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 1.5rem;
    display: flex;
    align-items: center;
    gap: 1.25rem;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    transition: transform 0.2s, box-shadow 0.2s;
}

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

.kpi-icon {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
}

.color-red { background-color: #fee2e2; color: #ef4444; }
.color-orange { background-color: #ffedd5; color: #f97316; }
.color-yellow { background-color: #fef3c7; color: #d97706; }
.color-green { background-color: #d1fae5; color: #10b981; }

.kpi-info h3 {
    font-size: 0.875rem;
    color: var(--text-muted);
    font-weight: 500;
}

.kpi-value {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-main);
    margin-top: 0.25rem;
}

.warning-pulse {
    animation: pulseRed 2s infinite;
}

/* Cards & Layout */
.card {
    background: var(--card-bg);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    margin-bottom: 2rem;
    overflow: hidden;
}

.card-header {
    padding: 1.25rem 1.5rem;
    border-bottom: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: #fafafa;
}

.card-header h3 {
    font-size: 1.1rem;
    font-weight: 600;
    color: #1e293b;
}

.grid-layout {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

@media (max-width: 768px) {
    .grid-layout {
        grid-template-columns: 1fr;
    }
    .view-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }
}

/* Tables */
.table-responsive {
    overflow-x: auto;
    width: 100%;
}

.data-table {
    width: 100%;
    border-collapse: collapse;
    text-align: left;
    font-size: 0.9rem;
}

.data-table th {
    background-color: #f8fafc;
    color: var(--text-muted);
    font-weight: 600;
    padding: 1rem 1.5rem;
    border-bottom: 1px solid var(--border);
    text-transform: uppercase;
    font-size: 0.75rem;
    letter-spacing: 0.05em;
}

.data-table td {
    padding: 1rem 1.5rem;
    border-bottom: 1px solid var(--border);
    color: #334155;
    vertical-align: middle;
}

.data-table tbody tr:hover {
    background-color: #f8fafc;
}

/* Badges */
.badge {
    display: inline-flex;
    align-items: center;
    padding: 0.25rem 0.75rem;
    border-radius: 9999px;
    font-size: 0.75rem;
    font-weight: 600;
}

.badge-danger { background-color: #fee2e2; color: #ef4444; }
.badge-warning { background-color: #fef3c7; color: #d97706; }
.badge-success { background-color: #d1fae5; color: #10b981; }
.badge-secondary { background-color: #f1f5f9; color: #475569; }

/* Forms & Inputs */
.form-group {
    margin-bottom: 1.25rem;
    padding: 0 1.5rem;
}

#leave-form .form-group {
    padding: 0;
}

#leave-form {
    padding: 1.5rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    font-size: 0.875rem;
    font-weight: 500;
    color: #475569;
}

.form-control {
    width: 100%;
    padding: 0.625rem 0.875rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-family: inherit;
    font-size: 0.9rem;
    outline: none;
    transition: border-color 0.2s, box-shadow 0.2s;
}

.form-control:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}

.form-control-inline {
    padding: 0.4rem 0.8rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-family: inherit;
    font-size: 0.9rem;
    outline: none;
    background-color: white;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0.625rem 1.25rem;
    border-radius: 8px;
    font-family: inherit;
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    border: none;
    transition: background-color 0.2s, transform 0.1s;
    gap: 0.5rem;
}

.btn-block {
    width: 100%;
}

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

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

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

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

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

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

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

.btn-outline {
    background-color: transparent;
    border: 1px solid var(--border);
    color: var(--text-main);
}

.btn-outline:hover {
    background-color: #f1f5f9;
}

.btn-sm {
    padding: 0.35rem 0.75rem;
    font-size: 0.8rem;
    border-radius: 6px;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(15, 23, 42, 0.4);
    backdrop-filter: blur(4px);
    align-items: center;
    justify-content: center;
}

.modal.active {
    display: flex;
}

.modal-content {
    background-color: white;
    border-radius: var(--radius);
    width: 90%;
    max-width: 500px;
    padding: 2rem 0;
    box-shadow: var(--shadow-lg);
    position: relative;
    animation: modalSlide 0.3s ease-out forwards;
}

.modal-content h2 {
    font-size: 1.25rem;
    margin-bottom: 0.5rem;
    padding: 0 2rem;
    font-weight: 700;
}

.modal-content p {
    padding: 0 2rem;
    margin-bottom: 1.5rem;
}

.close-btn {
    position: absolute;
    top: 1rem;
    right: 1.5rem;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-muted);
}

.close-btn:hover {
    color: var(--text-main);
}

/* Alerts */
.alert-info {
    background-color: #eff6ff;
    border-left: 4px solid #3b82f6;
    color: #1e3a8a;
    padding: 0.75rem 1rem;
    border-radius: 4px;
    margin: 1rem 1.5rem;
    font-size: 0.85rem;
}

#leave-form .alert-info {
    margin: 1rem 0;
}

/* List Items (Teacher View) */
.list-container {
    padding: 1rem;
    max-height: 350px;
    overflow-y: auto;
}

.list-item {
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 1rem;
    margin-bottom: 0.75rem;
    background-color: #fafafa;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.list-item-info h4 {
    font-size: 0.95rem;
    font-weight: 600;
}

.list-item-info p {
    font-size: 0.8rem;
    color: var(--text-muted);
    margin-top: 0.25rem;
}

/* Toast */
.toast {
    visibility: hidden;
    min-width: 250px;
    background-color: #0f172a;
    color: #fff;
    text-align: center;
    border-radius: 8px;
    padding: 1rem;
    position: fixed;
    z-index: 2000;
    left: 50%;
    bottom: 30px;
    transform: translateX(-50%);
    font-size: 0.9rem;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    transition: opacity 0.3s, visibility 0.3s;
}

.toast.show {
    visibility: visible;
    opacity: 1;
}

/* Animations */
@keyframes float {
    0% { transform: translateY(0px); }
    50% { transform: translateY(-5px); }
    100% { transform: translateY(0px); }
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes modalSlide {
    from { opacity: 0; transform: translateY(30px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes pulseRed {
    0% { transform: scale(1); }
    50% { transform: scale(1.05); color: #ef4444; }
    100% { transform: scale(1); }
}