/* ============================================
   Modern Ders Programı Sistemi - CSS
   Tasarım: Soft, yumuşak, güven veren
   ============================================ */

:root {
    /* Ana Renk Paleti - Soft & Professional */
    --primary-color: #6366f1;
    --primary-light: #818cf8;
    --primary-dark: #4f46e5;
    --secondary-color: #8b5cf6;
    --accent-color: #06b6d4;
    
    /* Nötr Renkler */
    --bg-primary: #f8fafc;
    --bg-secondary: #ffffff;
    --bg-sidebar: #1e293b;
    --text-primary: #0f172a;
    --text-secondary: #64748b;
    --text-light: #94a3b8;
    
    /* Durum Renkleri */
    --success: #10b981;
    --warning: #f59e0b;
    --danger: #ef4444;
    --info: #3b82f6;
    
    /* Gölgeler */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    
    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    
    /* Transitions */
    --transition-fast: 150ms ease-in-out;
    --transition-base: 250ms ease-in-out;
    --transition-slow: 350ms ease-in-out;
}

/* ============================================
   Global Styles
   ============================================ */

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    overflow-x: hidden;
}

main {
    flex: 1;
}

/* ============================================
   Typography
   ============================================ */

h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.2;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
}

h1 { font-size: 2.25rem; }
h2 { font-size: 1.875rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }
h5 { font-size: 1.125rem; }
h6 { font-size: 1rem; }

p {
    margin-bottom: var(--spacing-sm);
    color: var(--text-secondary);
}

/* ============================================
   Animations
   ============================================ */

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

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

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

@keyframes scaleIn {
    from {
        opacity: 0;
        transform: scale(0.95);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

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

.slide-in-right {
    animation: slideInRight var(--transition-base);
}

.slide-in-left {
    animation: slideInLeft var(--transition-base);
}

.scale-in {
    animation: scaleIn var(--transition-base);
}

/* ============================================
   Navigation / Header
   ============================================ */

.navbar {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%) !important;
    box-shadow: var(--shadow-md);
    padding: 1rem 0;
}

.navbar-brand {
    font-weight: 700;
    font-size: 1.5rem;
    color: white !important;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: transform var(--transition-fast);
}

.navbar-brand:hover {
    transform: scale(1.05);
}

.nav-link {
    color: rgba(255, 255, 255, 0.9) !important;
    font-weight: 500;
    padding: 0.5rem 1rem !important;
    border-radius: var(--radius-md);
    transition: all var(--transition-fast);
    position: relative;
}

.nav-link:hover,
.nav-link.active {
    background: rgba(255, 255, 255, 0.1);
    color: white !important;
    transform: translateY(-2px);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%) scaleX(0);
    width: 80%;
    height: 2px;
    background: white;
    transition: transform var(--transition-base);
}

.nav-link:hover::after {
    transform: translateX(-50%) scaleX(1);
}

/* ============================================
   Admin Layout with Sidebar
   ============================================ */

.admin-layout {
    display: flex;
    min-height: calc(100vh - 76px);
    background: var(--bg-primary);
}

.admin-sidebar {
    width: 280px;
    background: var(--bg-sidebar);
    color: white;
    padding: var(--spacing-lg) 0;
    box-shadow: var(--shadow-lg);
    position: sticky;
    top: 0;
    height: calc(100vh - 76px);
    overflow-y: auto;
    transition: all var(--transition-base);
}

.admin-sidebar::-webkit-scrollbar {
    width: 6px;
}

.admin-sidebar::-webkit-scrollbar-track {
    background: rgba(255, 255, 255, 0.05);
}

.admin-sidebar::-webkit-scrollbar-thumb {
    background: rgba(255, 255, 255, 0.2);
    border-radius: 3px;
}

.admin-sidebar::-webkit-scrollbar-thumb:hover {
    background: rgba(255, 255, 255, 0.3);
}

.sidebar-brand {
    padding: 0 var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    font-size: 1.25rem;
    font-weight: 700;
    color: white;
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    padding-bottom: var(--spacing-md);
}

.sidebar-menu {
    list-style: none;
    padding: 0;
    margin: 0;
}

.sidebar-menu-item {
    margin-bottom: 0.25rem;
}

.sidebar-menu-link {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 0.875rem var(--spacing-lg);
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    transition: all var(--transition-fast);
    position: relative;
    font-weight: 500;
}

.sidebar-menu-link::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 4px;
    height: 0;
    background: var(--accent-color);
    transition: height var(--transition-base);
    border-radius: 0 4px 4px 0;
}

.sidebar-menu-link:hover,
.sidebar-menu-link.active {
    background: rgba(255, 255, 255, 0.1);
    color: white;
    padding-left: calc(var(--spacing-lg) + 0.5rem);
}

.sidebar-menu-link.active::before,
.sidebar-menu-link:hover::before {
    height: 100%;
}

.sidebar-menu-icon {
    font-size: 1.25rem;
    width: 24px;
    text-align: center;
}

.admin-content {
    flex: 1;
    padding: var(--spacing-lg);
    animation: fadeIn var(--transition-base);
}

/* ============================================
   Cards
   ============================================ */

.card {
    background: var(--bg-secondary);
    border: none;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    margin-bottom: var(--spacing-md);
    overflow: hidden;
    transition: all var(--transition-base);
}

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

.card-header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-light) 100%);
    color: white;
    border: none;
    padding: 1.25rem 1.5rem;
    font-weight: 600;
    font-size: 1.125rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.card-body {
    padding: 1.5rem;
}

.card-footer {
    background: var(--bg-primary);
    border-top: 1px solid #e2e8f0;
    padding: 1rem 1.5rem;
}

/* Stats Cards */
.stat-card {
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    padding: 1.5rem;
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
    border-left: 4px solid var(--primary-color);
    animation: fadeIn var(--transition-base);
}

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

.stat-card.primary {
    border-left-color: var(--primary-color);
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.05) 0%, transparent 100%);
}

.stat-card.success {
    border-left-color: var(--success);
    background: linear-gradient(135deg, rgba(16, 185, 129, 0.05) 0%, transparent 100%);
}

.stat-card.warning {
    border-left-color: var(--warning);
    background: linear-gradient(135deg, rgba(245, 158, 11, 0.05) 0%, transparent 100%);
}

.stat-card.info {
    border-left-color: var(--info);
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.05) 0%, transparent 100%);
}

.stat-card.danger {
    border-left-color: var(--danger);
    background: linear-gradient(135deg, rgba(239, 68, 68, 0.05) 0%, transparent 100%);
}

.stat-icon {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
    opacity: 0.9;
}

.stat-value {
    font-size: 2.25rem;
    font-weight: 700;
    color: var(--text-primary);
    margin: 0;
    line-height: 1;
}

.stat-label {
    color: var(--text-secondary);
    font-size: 0.875rem;
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-top: 0.5rem;
}

/* ============================================
   Buttons
   ============================================ */

.btn {
    border: none;
    border-radius: var(--radius-md);
    padding: 0.625rem 1.5rem;
    font-weight: 600;
    font-size: 0.875rem;
    transition: all var(--transition-fast);
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    position: relative;
    overflow: hidden;
}

.btn::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    border-radius: 50%;
    background: rgba(255, 255, 255, 0.3);
    transform: translate(-50%, -50%);
    transition: width var(--transition-base), height var(--transition-base);
}

.btn:hover::before {
    width: 300px;
    height: 300px;
}

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

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-light) 100%);
    color: white;
}

.btn-primary:hover {
    box-shadow: 0 4px 12px rgba(99, 102, 241, 0.4);
    transform: translateY(-2px);
}

.btn-success {
    background: linear-gradient(135deg, var(--success) 0%, #059669 100%);
    color: white;
}

.btn-success:hover {
    box-shadow: 0 4px 12px rgba(16, 185, 129, 0.4);
    transform: translateY(-2px);
}

.btn-danger {
    background: linear-gradient(135deg, var(--danger) 0%, #dc2626 100%);
    color: white;
}

.btn-danger:hover {
    box-shadow: 0 4px 12px rgba(239, 68, 68, 0.4);
    transform: translateY(-2px);
}

.btn-warning {
    background: linear-gradient(135deg, var(--warning) 0%, #d97706 100%);
    color: white;
}

.btn-warning:hover {
    box-shadow: 0 4px 12px rgba(245, 158, 11, 0.4);
    transform: translateY(-2px);
}

.btn-info {
    background: linear-gradient(135deg, var(--info) 0%, #2563eb 100%);
    color: white;
}

.btn-info:hover {
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.4);
    transform: translateY(-2px);
}

.btn-secondary {
    background: #6b7280;
    color: white;
}

.btn-secondary:hover {
    background: #4b5563;
    transform: translateY(-2px);
}

.btn-outline {
    background: transparent;
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
}

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

.btn-sm {
    padding: 0.375rem 1rem;
    font-size: 0.8125rem;
}

.btn-lg {
    padding: 0.875rem 2rem;
    font-size: 1rem;
}

/* ============================================
   Forms
   ============================================ */

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--text-primary);
    font-size: 0.875rem;
}

.form-control,
.form-select {
    width: 100%;
    padding: 0.75rem 1rem;
    border: 2px solid #e2e8f0;
    border-radius: var(--radius-md);
    font-size: 0.9375rem;
    transition: all var(--transition-fast);
    background: var(--bg-secondary);
    color: var(--text-primary);
}

.form-control:focus,
.form-select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
    transform: translateY(-1px);
}

.form-control::placeholder {
    color: var(--text-light);
}

textarea.form-control {
    resize: vertical;
    min-height: 100px;
}

.form-group {
    margin-bottom: var(--spacing-md);
}

/* ============================================
   Tables
   ============================================ */

.table-responsive {
    overflow-x: auto;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}

.table {
    width: 100%;
    background: var(--bg-secondary);
    border-collapse: separate;
    border-spacing: 0;
}

.table thead {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-light) 100%);
    color: white;
}

.table thead th {
    padding: 1rem 1.5rem;
    font-weight: 600;
    text-align: left;
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    border: none;
}

.table tbody td {
    padding: 1rem 1.5rem;
    border-bottom: 1px solid #e2e8f0;
    color: var(--text-secondary);
}

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

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

.table tbody tr:last-child td {
    border-bottom: none;
}

/* Schedule Table */
.schedule-table {
    width: 100%;
    border-collapse: collapse;
    background: var(--bg-secondary);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
}

.schedule-table th {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-light) 100%);
    color: white;
    padding: 1rem;
    text-align: center;
    font-weight: 600;
    font-size: 0.9375rem;
}

.schedule-table td {
    border: 1px solid #e2e8f0;
    padding: 0.75rem;
    text-align: center;
    min-width: 120px;
    min-height: 80px;
    vertical-align: top;
    transition: all var(--transition-fast);
    position: relative;
}

.schedule-table td:hover {
    background: var(--bg-primary);
    cursor: pointer;
}

.schedule-table .time-cell {
    background: var(--bg-primary);
    font-weight: 600;
    color: var(--text-primary);
}

.schedule-cell {
    background: linear-gradient(135deg, rgba(99, 102, 241, 0.1) 0%, rgba(129, 140, 248, 0.05) 100%);
    border-radius: var(--radius-sm);
    padding: 0.5rem;
    font-size: 0.8125rem;
    font-weight: 500;
    color: var(--primary-dark);
    border-left: 3px solid var(--primary-color);
    text-align: left;
    transition: all var(--transition-fast);
}

.schedule-cell:hover {
    transform: scale(1.05);
    box-shadow: var(--shadow-md);
}

.schedule-cell-course {
    font-weight: 700;
    margin-bottom: 0.25rem;
}

.schedule-cell-teacher {
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.schedule-cell-empty {
    color: var(--text-light);
    font-style: italic;
}

/* ============================================
   Badges
   ============================================ */

.badge {
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    padding: 0.375rem 0.75rem;
    border-radius: var(--radius-md);
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.badge-primary {
    background: rgba(99, 102, 241, 0.1);
    color: var(--primary-dark);
}

.badge-success {
    background: rgba(16, 185, 129, 0.1);
    color: #047857;
}

.badge-warning {
    background: rgba(245, 158, 11, 0.1);
    color: #b45309;
}

.badge-danger {
    background: rgba(239, 68, 68, 0.1);
    color: #b91c1c;
}

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

/* ============================================
   Alerts
   ============================================ */

.alert {
    padding: 1rem 1.25rem;
    border-radius: var(--radius-lg);
    border: none;
    margin-bottom: var(--spacing-md);
    display: flex;
    align-items: center;
    gap: 0.75rem;
    animation: slideInRight var(--transition-base);
    box-shadow: var(--shadow-sm);
}

.alert-success {
    background: linear-gradient(135deg, rgba(16, 185, 129, 0.1) 0%, rgba(16, 185, 129, 0.05) 100%);
    color: #047857;
    border-left: 4px solid var(--success);
}

.alert-danger {
    background: linear-gradient(135deg, rgba(239, 68, 68, 0.1) 0%, rgba(239, 68, 68, 0.05) 100%);
    color: #b91c1c;
    border-left: 4px solid var(--danger);
}

.alert-warning {
    background: linear-gradient(135deg, rgba(245, 158, 11, 0.1) 0%, rgba(245, 158, 11, 0.05) 100%);
    color: #b45309;
    border-left: 4px solid var(--warning);
}

.alert-info {
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.1) 0%, rgba(59, 130, 246, 0.05) 100%);
    color: #1e40af;
    border-left: 4px solid var(--info);
}

/* ============================================
   Modal
   ============================================ */

.modal-content {
    border: none;
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
    overflow: hidden;
}

.modal-header {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-light) 100%);
    color: white;
    border: none;
    padding: 1.5rem;
}

.modal-title {
    font-weight: 700;
    font-size: 1.25rem;
}

.modal-body {
    padding: 1.5rem;
}

.modal-footer {
    border-top: 1px solid #e2e8f0;
    padding: 1rem 1.5rem;
    background: var(--bg-primary);
}

.btn-close {
    filter: brightness(0) invert(1);
    opacity: 0.8;
}

.btn-close:hover {
    opacity: 1;
}

/* ============================================
   Footer
   ============================================ */

footer {
    background: var(--bg-secondary);
    border-top: 1px solid #e2e8f0;
    padding: 1.5rem 0;
    margin-top: auto;
}

footer .text-muted {
    color: var(--text-secondary) !important;
}

/* ============================================
   Empty State
   ============================================ */

.empty-state {
    padding: 3rem 2rem;
    text-align: center;
    color: var(--text-secondary);
}

.empty-state-icon {
    font-size: 4rem;
    opacity: 0.3;
    margin-bottom: 1rem;
}

.empty-state p {
    font-size: 1.125rem;
    margin: 0;
}

/* ============================================
   Loading States
   ============================================ */

.loading {
    opacity: 0.6;
    pointer-events: none;
    position: relative;
}

.spinner-border-sm {
    width: 1rem;
    height: 1rem;
    border-width: 0.15em;
}

/* ============================================
   Responsive Design
   ============================================ */

@media (max-width: 992px) {
    .admin-sidebar {
        width: 240px;
    }
    
    .sidebar-menu-link {
        padding: 0.75rem var(--spacing-md);
    }
}

@media (max-width: 768px) {
    .admin-layout {
        flex-direction: column;
    }
    
    .admin-sidebar {
        width: 100%;
        height: auto;
        position: relative;
    }
    
    .admin-content {
        padding: var(--spacing-md);
    }
    
    h1 { font-size: 1.75rem; }
    h2 { font-size: 1.5rem; }
    h3 { font-size: 1.25rem; }
    
    .stat-value {
        font-size: 1.75rem;
    }
    
    .schedule-table {
        font-size: 0.75rem;
    }
    
    .schedule-table td {
        min-width: 80px;
        padding: 0.5rem;
    }
}

/* ============================================
   Utility Classes
   ============================================ */

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

.mt-1 { margin-top: 0.25rem; }
.mt-2 { margin-top: 0.5rem; }
.mt-3 { margin-top: 1rem; }
.mt-4 { margin-top: 1.5rem; }
.mt-5 { margin-top: 3rem; }

.mb-1 { margin-bottom: 0.25rem; }
.mb-2 { margin-bottom: 0.5rem; }
.mb-3 { margin-bottom: 1rem; }
.mb-4 { margin-bottom: 1.5rem; }
.mb-5 { margin-bottom: 3rem; }

.p-1 { padding: 0.25rem; }
.p-2 { padding: 0.5rem; }
.p-3 { padding: 1rem; }
.p-4 { padding: 1.5rem; }
.p-5 { padding: 3rem; }

.d-flex { display: flex; }
.d-block { display: block; }
.d-inline-block { display: inline-block; }
.d-none { display: none; }

.justify-content-between { justify-content: space-between; }
.justify-content-center { justify-content: center; }
.justify-content-end { justify-content: flex-end; }

.align-items-center { align-items: center; }
.align-items-start { align-items: flex-start; }
.align-items-end { align-items: flex-end; }

.gap-1 { gap: 0.25rem; }
.gap-2 { gap: 0.5rem; }
.gap-3 { gap: 1rem; }

.w-100 { width: 100%; }
.h-100 { height: 100%; }

.rounded { border-radius: var(--radius-md); }
.rounded-lg { border-radius: var(--radius-lg); }
.rounded-xl { border-radius: var(--radius-xl); }

.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); }

.hover-card {
    transition: all 0.3s ease;
}

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