/* =====================================================
   TDMU Smart Scheduler - Premium UI Design System
   Modern, Beautiful, Responsive
   ===================================================== */

/* Google Fonts */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&display=swap');

/* ===== CSS VARIABLES ===== */
:root {
    /* Colors - Premium Palette */
    --primary: #667eea;
    --primary-dark: #5568d3;
    --primary-light: #818cf8;
    --secondary: #764ba2;
    --accent: #f093fb;
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --info: #3b82f6;

    /* Backgrounds */
    --bg-primary: #f8f9fc;
    --bg-secondary: #ffffff;
    --bg-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --bg-gradient-light: linear-gradient(135deg, rgba(102, 126, 234, 0.1) 0%, rgba(118, 75, 162, 0.1) 100%);

    /* Text */
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --text-muted: #94a3b8;

    /* Borders & Shadows */
    --border-color: rgba(0, 0, 0, 0.08);
    --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.12);
    --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.16);

    /* Radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --radius-full: 9999px;

    /* Spacing */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;

    /* Transitions */
    --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 250ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 350ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* ===== GLOBAL STYLES ===== */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html,
body {
    height: 100%;
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    font-size: 15px;
    line-height: 1.6;
    color: var(--text-primary);
    background: var(--bg-primary);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ===== NAVIGATION ===== */
.scheduler-navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 72px;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
    transition: all var(--transition-base);
}

.scheduler-navbar:hover {
    box-shadow: var(--shadow-md);
}

.nav-inner {
    max-width: 1280px;
    height: 100%;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--spacing-lg);
}

.header-left {
    display: flex;
    align-items: center;
    gap: var(--spacing-xl);
}

.header-title {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1.25rem;
    font-weight: 800;
    background: var(--bg-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    text-decoration: none;
    transition: transform var(--transition-fast);
}

.header-title:hover {
    transform: scale(1.05);
}

.header-title i {
    font-size: 1.5rem;
    background: var(--bg-gradient);

    /* Standard syntax (future-proof) */
    background-clip: text;

    /* Vendor prefixes for current browsers */
    -webkit-background-clip: text;

    /* Required for transparent text effect */
    color: transparent;
    -webkit-text-fill-color: transparent;
}

/* Nav Tabs */
.nav-tabs-container {
    display: flex;
    gap: var(--spacing-sm);
    align-items: center;
}

.tab-button {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: 10px 18px;
    border-radius: var(--radius-full);
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--text-secondary);
    text-decoration: none;
    border: 2px solid transparent;
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.tab-button::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--bg-gradient);
    opacity: 0;
    transition: opacity var(--transition-base);
    z-index: -1;
}

.tab-button.active {
    color: white;
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.tab-button.active::before {
    opacity: 1;
}

.tab-button:hover:not(.active) {
    color: var(--primary);
    background: var(--bg-gradient-light);
    transform: translateY(-2px);
}

/* Header Right */
.header-right {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

/* Buttons */
.btn-rounded {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: 10px 20px;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 0.9rem;
    text-decoration: none;
    border: 2px solid transparent;
    cursor: pointer;
    transition: all var(--transition-base);
    position: relative;
    overflow: hidden;
}

.btn-rounded::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(135deg, rgba(255, 255, 255, 0.2), transparent);
    opacity: 0;
    transition: opacity var(--transition-base);
}

.btn-rounded:hover::before {
    opacity: 1;
}

.btn-rounded:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.btn-rounded:active {
    transform: translateY(-1px);
}

.btn-cyan {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-pink {
    background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    color: white;
    box-shadow: var(--shadow-md);
}

.btn-icon {
    width: 44px;
    height: 44px;
    padding: 0;
    justify-content: center;
    border-radius: var(--radius-md);
    background: white;
    border: 2px solid var(--border-color);
}

.btn-icon:hover {
    background: var(--bg-gradient-light);
    border-color: var(--primary);
}

/* Dropdown */
.dropdown-menu {
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-xl);
    padding: var(--spacing-sm);
    min-width: 200px;
    animation: slideDown var(--transition-base);
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.dropdown-item {
    padding: 10px 16px;
    border-radius: var(--radius-sm);
    font-weight: 500;
    transition: all var(--transition-fast);
}

.dropdown-item:hover {
    background: var(--bg-gradient-light);
    color: var(--primary);
}

/* ===== LAYOUT ===== */
.nav-spacer {
    height: 88px;
}

.scheduler-page-container {
    max-width: 1280px;
    margin: 0 auto;
    padding: var(--spacing-xl);
}

/* ===== CARDS ===== */
.card {
    background: white;
    border-radius: var(--radius-lg);
    border: 1px solid var(--border-color);
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
}

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

.card-header {
    padding: var(--spacing-lg);
    border-bottom: 1px solid var(--border-color);
    font-weight: 600;
}

.card-body {
    padding: var(--spacing-lg);
}

/* Glass Card */
.glass-card {
    background: rgba(255, 255, 255, 0.7);
    backdrop-filter: blur(12px);
    border: 1px solid rgba(255, 255, 255, 0.3);
    box-shadow: var(--shadow-lg);
}

/* Gradient Card */
.gradient-card {
    background: var(--bg-gradient);
    color: white;
}

.gradient-card .card-header {
    border-bottom-color: rgba(255, 255, 255, 0.2);
}

/* ===== FORMS ===== */
.form-control {
    padding: 12px 16px;
    border-radius: var(--radius-md);
    border: 2px solid var(--border-color);
    font-size: 0.95rem;
    transition: all var(--transition-base);
    background: white;
}

.form-control:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(102, 126, 234, 0.1);
}

.form-label {
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
    display: block;
}

.form-select {
    padding: 12px 16px;
    border-radius: var(--radius-md);
    border: 2px solid var(--border-color);
    background: white;
    cursor: pointer;
    transition: all var(--transition-base);
}

.form-select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(102, 126, 234, 0.1);
}

/* ===== BADGES ===== */
.badge {
    padding: 6px 12px;
    border-radius: var(--radius-full);
    font-weight: 600;
    font-size: 0.85rem;
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
}

.bg-primary {
    background: var(--bg-gradient) !important;
}

.bg-success {
    background: var(--success) !important;
}

.bg-warning {
    background: var(--warning) !important;
}

.bg-danger {
    background: var(--danger) !important;
}

.bg-info {
    background: var(--info) !important;
}

/* ===== ALERTS ===== */
.alert {
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-md);
    border-left: 4px solid;
    animation: slideIn var(--transition-base);
}

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

    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.alert-success {
    background: rgba(16, 185, 129, 0.1);
    border-color: var(--success);
    color: #065f46;
}

.alert-warning {
    background: rgba(245, 158, 11, 0.1);
    border-color: var(--warning);
    color: #92400e;
}

.alert-danger {
    background: rgba(239, 68, 68, 0.1);
    border-color: var(--danger);
    color: #991b1b;
}

.alert-info {
    background: rgba(59, 130, 246, 0.1);
    border-color: var(--info);
    color: #1e40af;
}

/* ===== TABLES ===== */
.table {
    border-radius: var(--radius-md);
    overflow: hidden;
}

.table thead {
    background: var(--bg-gradient-light);
}

.table th {
    font-weight: 600;
    padding: 16px;
    border-bottom: 2px solid var(--border-color);
}

.table td {
    padding: 14px 16px;
    border-bottom: 1px solid var(--border-color);
}

.table-hover tbody tr {
    transition: all var(--transition-fast);
}

.table-hover tbody tr:hover {
    background: var(--bg-gradient-light);
    transform: scale(1.01);
}

/* ===== FOOTER ===== */
.main-footer {
    margin-top: var(--spacing-xl);
    padding: var(--spacing-xl) 0;
    text-align: center;
    background: var(--bg-gradient-light);
    color: var(--text-secondary);
    border-top: 1px solid var(--border-color);
}

.footer-text {
    margin-top: var(--spacing-sm);
    font-size: 0.9rem;
}

/* ===== UTILITIES ===== */
.text-gradient {
    background: var(--bg-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.shadow-sm {
    box-shadow: var(--shadow-sm);
}

.shadow-md {
    box-shadow: var(--shadow-md);
}

.shadow-lg {
    box-shadow: var(--shadow-lg);
}

.shadow-xl {
    box-shadow: var(--shadow-xl);
}

/* ===== ANIMATIONS ===== */
@keyframes fadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

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

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.animate-fade-in {
    animation: fadeIn var(--transition-base);
}

.animate-slide-up {
    animation: slideUp var(--transition-base);
}

/* ===== RESPONSIVE ===== */
@media (max-width: 1024px) {
    .scheduler-page-container {
        padding: var(--spacing-lg);
    }
}

@media (max-width: 768px) {
    .nav-tabs-container {
        display: none;
    }

    .header-title {
        font-size: 1.1rem;
    }

    .scheduler-page-container {
        padding: var(--spacing-md);
    }

    .btn-rounded {
        padding: 8px 16px;
        font-size: 0.85rem;
    }
}

/* ===== UTILITIES OVERRIDES ===== */
/* Make bg-light visible on white backgrounds */
.bg-light {
    background-color: #e2e8f0 !important;
    /* Slate 200 - Visible on white */
    color: #1e293b !important;
    /* Slate 800 - Contrast text */
}

.text-dark {
    color: #0f172a !important;
    /* Slate 900 */
}

/* ===== ACCESSIBILITY ===== */
*:focus-visible {
    outline: 3px solid rgba(102, 126, 234, 0.4);
    outline-offset: 2px;
}

/* ===== LOADING SPINNER ===== */
.spinner-border {
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}