@import url('https://fonts.googleapis.com/css2?family=Outfit:wght@300;400;500;600;700&display=swap');

:root {
    --bg-primary: #f8fafc;
    --bg-secondary: #ffffff;
    --bg-card: rgba(255, 255, 255, 0.85);
    --bg-card-hover: rgba(255, 255, 255, 0.98);
    --border-color: rgba(0, 0, 0, 0.08);
    --border-hover: rgba(0, 0, 0, 0.16);
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --primary-glow: rgba(37, 99, 235, 0.08);
    --secondary: #0284c7;
    --secondary-hover: #0369a1;
    --secondary-glow: rgba(2, 132, 199, 0.08);
    --text-main: #0f172a;
    --text-muted: #64748b;
    --success: #059669;
    --success-glow: rgba(5, 150, 105, 0.12);
    --danger: #dc2626;
    --danger-glow: rgba(220, 38, 38, 0.12);
    --warning: #d97706;
    --warning-glow: rgba(217, 119, 6, 0.12);
    --card-shadow: 0 10px 30px rgba(15, 23, 42, 0.06);
    --glass-blur: blur(10px);
    --radius-sm: 8px;
    --radius-md: 14px;
    --radius-lg: 20px;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-fast: all 0.15s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Outfit', sans-serif;
}

body {
    background-color: var(--bg-primary);
    color: var(--text-main);
    min-height: 100vh;
    overflow-x: hidden;
    background-image: 
        radial-gradient(circle at 10% 20%, rgba(37, 99, 235, 0.03) 0%, transparent 40%),
        radial-gradient(circle at 90% 80%, rgba(2, 132, 199, 0.03) 0%, transparent 45%);
    background-attachment: fixed;
}

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}
::-webkit-scrollbar-track {
    background: var(--bg-primary);
}
::-webkit-scrollbar-thumb {
    background: rgba(0, 0, 0, 0.15);
    border-radius: var(--radius-sm);
}
::-webkit-scrollbar-thumb:hover {
    background: rgba(0, 0, 0, 0.25);
}

/* Hide Elements */
.hidden {
    display: none !important;
}

/* Flex & Grid Helpers */
.flex-row-center {
    display: flex;
    align-items: center;
    justify-content: center;
}

.flex-between {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

/* Global App container */
#app-container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Glass Card Style */
.glass-card {
    background: var(--bg-card);
    backdrop-filter: var(--glass-blur);
    -webkit-backdrop-filter: var(--glass-blur);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    box-shadow: var(--card-shadow);
    transition: var(--transition);
}

.glass-card:hover {
    border-color: var(--border-hover);
}

/* Buttons */
.btn {
    padding: 10px 20px;
    border-radius: var(--radius-sm);
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
    border: 1px solid transparent;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    font-size: 0.95rem;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary) 0%, #1d4ed8 100%);
    color: #fff;
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.2);
}
.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(37, 99, 235, 0.35);
}

.btn-secondary {
    background: rgba(0, 0, 0, 0.04);
    color: var(--text-main);
    border-color: var(--border-color);
}
.btn-secondary:hover {
    background: rgba(0, 0, 0, 0.08);
    border-color: var(--border-hover);
}

.btn-accent {
    background: linear-gradient(135deg, var(--secondary) 0%, #0369a1 100%);
    color: #fff;
    box-shadow: 0 4px 12px rgba(2, 132, 199, 0.2);
}
.btn-accent:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(2, 132, 199, 0.35);
}

.btn-danger {
    background: rgba(244, 63, 94, 0.15);
    color: var(--danger);
    border: 1px solid rgba(244, 63, 94, 0.2);
}
.btn-danger:hover {
    background: var(--danger);
    color: #fff;
}

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

/* Forms */
.form-group {
    margin-bottom: 20px;
    position: relative;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-muted);
}

.form-control {
    width: 100%;
    padding: 12px 16px;
    background: #ffffff;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-main);
    font-size: 0.95rem;
    transition: var(--transition);
}

.form-control:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px var(--primary-glow);
    background: #ffffff;
}

.form-control::placeholder {
    color: rgba(15, 23, 42, 0.4);
}

select.form-control {
    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='%2394a3b8'%3E%3Cpath stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M19 9l-7 7-7-7'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 16px center;
    background-size: 16px;
    padding-right: 40px;
}

/* Toast Notification */
.toast-container {
    position: fixed;
    top: 24px;
    right: 24px;
    z-index: 9999;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.toast {
    padding: 16px 20px;
    background: #ffffff;
    border-left: 4px solid var(--primary);
    border-radius: 6px;
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.08);
    color: var(--text-main);
    display: flex;
    align-items: center;
    gap: 12px;
    border: 1px solid var(--border-color);
    animation: slideIn 0.3s cubic-bezier(0.34, 1.56, 0.64, 1) forwards;
}

.toast.success { border-left-color: var(--success); }
.toast.error { border-left-color: var(--danger); }
.toast.info { border-left-color: var(--secondary); }

@keyframes slideIn {
    from { transform: translateX(120%); opacity: 0; }
    to { transform: translateX(0); opacity: 1; }
}

/* Auth Pages (Login / Register) */
.auth-wrapper {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 40px 20px;
    min-height: 100vh;
}

.auth-card {
    width: 100%;
    max-width: 500px;
    padding: 40px;
}

.auth-header {
    text-align: center;
    margin-bottom: 30px;
}

.auth-header h1 {
    font-size: 2.2rem;
    font-weight: 700;
    margin-bottom: 8px;
    background: linear-gradient(135deg, var(--text-main) 30%, var(--text-muted) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.auth-header p {
    color: var(--text-muted);
}

.auth-tabs {
    display: flex;
    background: rgba(0,0,0,0.05);
    padding: 4px;
    border-radius: var(--radius-sm);
    margin-bottom: 24px;
}

.auth-tab-btn {
    flex: 1;
    background: none;
    border: none;
    color: var(--text-muted);
    padding: 10px;
    font-size: 0.95rem;
    font-weight: 500;
    cursor: pointer;
    border-radius: 6px;
    transition: var(--transition-fast);
}

.auth-tab-btn.active {
    background: var(--primary);
    color: #fff;
    box-shadow: 0 4px 10px rgba(99, 102, 241, 0.2);
}

.auth-footer {
    text-align: center;
    margin-top: 24px;
    color: var(--text-muted);
    font-size: 0.9rem;
}

.auth-footer a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 500;
    margin-left: 4px;
    transition: var(--transition-fast);
}

.auth-footer a:hover {
    color: var(--primary-hover);
    text-decoration: underline;
}

/* Dashboard Layout */
.dashboard-wrapper {
    display: flex;
    min-height: 100vh;
}

/* Sidebar */
.sidebar {
    width: 280px;
    background: #ffffff;
    border-right: 1px solid var(--border-color);
    padding: 24px;
    display: flex;
    flex-direction: column;
    z-index: 100;
    box-shadow: 4px 0 20px rgba(0, 0, 0, 0.02);
}

.sidebar-logo {
    display: flex;
    align-items: center;
    gap: 12px;
    padding-bottom: 24px;
    border-bottom: 1px solid var(--border-color);
    margin-bottom: 24px;
}

.sidebar-logo-icon {
    width: 40px;
    height: 40px;
    border-radius: var(--radius-sm);
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-weight: 700;
    font-size: 1.3rem;
}

.sidebar-logo-text {
    font-size: 1.25rem;
    font-weight: 600;
    letter-spacing: 0.5px;
}

.sidebar-user {
    padding: 16px;
    background: rgba(0, 0, 0, 0.02);
    border-radius: var(--radius-sm);
    margin-bottom: 24px;
    border: 1px solid var(--border-color);
}

.sidebar-user-role {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--secondary);
    font-weight: 600;
    margin-bottom: 4px;
}

.sidebar-user-name {
    font-size: 0.95rem;
    font-weight: 500;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.sidebar-menu {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 6px;
    flex: 1;
}

.sidebar-menu-item a {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    border-radius: var(--radius-sm);
    color: var(--text-muted);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition-fast);
    cursor: pointer;
}

.sidebar-menu-item a:hover {
    color: var(--text-main);
    background: rgba(0, 0, 0, 0.03);
}

.sidebar-menu-item.active a {
    color: var(--primary);
    background: var(--primary-glow);
    border-left: 3px solid var(--primary);
    padding-left: 13px;
}

.sidebar-menu-item.active a svg {
    color: var(--primary);
}

.sidebar-menu-item svg {
    width: 20px;
    height: 20px;
    transition: var(--transition-fast);
}

.sidebar-footer {
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
    margin-top: auto;
}

/* Main Dashboard Area */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow-y: auto;
    height: 100vh;
}

.top-bar {
    padding: 20px 40px;
    background: rgba(255, 255, 255, 0.8);
    border-bottom: 1px solid var(--border-color);
    backdrop-filter: blur(10px);
}

.top-bar h2 {
    font-size: 1.5rem;
    font-weight: 600;
}

.content-pane {
    padding: 40px;
    flex: 1;
}

/* Dashboard Cards (Overview Stats) */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: 24px;
    margin-bottom: 40px;
}

.stat-card {
    padding: 24px;
    position: relative;
    overflow: hidden;
}

.stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: var(--primary);
}

.stat-card.cyan::before { background: var(--secondary); }
.stat-card.emerald::before { background: var(--success); }
.stat-card.amber::before { background: var(--warning); }

.stat-icon {
    width: 48px;
    height: 48px;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-color);
    color: var(--primary);
    margin-bottom: 16px;
}

.stat-card.cyan .stat-icon { color: var(--secondary); }
.stat-card.emerald .stat-icon { color: var(--success); }
.stat-card.amber .stat-icon { color: var(--warning); }

.stat-title {
    font-size: 0.9rem;
    color: var(--text-muted);
    font-weight: 500;
    margin-bottom: 6px;
}

.stat-value {
    font-size: 1.8rem;
    font-weight: 700;
}

/* Card Section Titles */
.section-header {
    margin-bottom: 24px;
}

.section-header h3 {
    font-size: 1.25rem;
    font-weight: 600;
}

.section-header p {
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-top: 4px;
}

/* Tables styling */
.table-responsive {
    overflow-x: auto;
    margin-bottom: 24px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-color);
}

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

.custom-table th {
    background: rgba(255, 255, 255, 0.02);
    padding: 16px 20px;
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--text-muted);
    border-bottom: 1px solid var(--border-color);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.custom-table td {
    padding: 16px 20px;
    font-size: 0.95rem;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-main);
}

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

.custom-table tbody tr:hover {
    background: rgba(255, 255, 255, 0.02);
}

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

/* Badges */
.badge {
    padding: 4px 10px;
    border-radius: 50px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    display: inline-flex;
    align-items: center;
    gap: 4px;
}

.badge-pending {
    background: var(--warning-glow);
    color: var(--warning);
}

.badge-approved {
    background: var(--success-glow);
    color: var(--success);
}

.badge-graded {
    background: var(--success-glow);
    color: var(--success);
}

.badge-submitted {
    background: var(--secondary-glow);
    color: var(--secondary);
}

/* Split Column Layouts */
.grid-2col {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 30px;
}

.grid-3col {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 30px;
}

/* Standard Panels */
.panel {
    padding: 30px;
    margin-bottom: 30px;
}

/* Notice board styling */
.notice-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.notice-item {
    padding: 20px;
    cursor: pointer;
}

.notice-meta {
    font-size: 0.8rem;
    color: var(--text-muted);
    display: flex;
    gap: 16px;
    margin-bottom: 8px;
}

.notice-meta span {
    display: flex;
    align-items: center;
    gap: 6px;
}

.notice-title {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 10px;
}

.notice-excerpt {
    color: var(--text-muted);
    font-size: 0.95rem;
    line-height: 1.5;
}

.notice-tag {
    background: rgba(37, 99, 235, 0.08);
    color: var(--primary);
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 500;
    text-transform: uppercase;
}

/* Question & File Cards */
.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 24px;
}

.item-card {
    padding: 24px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    height: 100%;
}

.item-subject {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    color: var(--secondary);
    letter-spacing: 0.5px;
    margin-bottom: 8px;
}

.item-title {
    font-size: 1.15rem;
    font-weight: 600;
    margin-bottom: 12px;
}

.item-desc {
    color: var(--text-muted);
    font-size: 0.9rem;
    line-height: 1.5;
    margin-bottom: 20px;
    flex: 1;
}

.item-footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-top: 1px solid var(--border-color);
    padding-top: 16px;
    margin-top: auto;
}

.item-date {
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* Modal Styling */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(15, 23, 42, 0.35);
    backdrop-filter: blur(8px);
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    animation: fadeIn 0.25s ease-out;
}

.modal-content {
    width: 100%;
    max-width: 650px;
    max-height: 85vh;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    animation: scaleUp 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.modal-content.large {
    max-width: 1000px;
}

.modal-header {
    padding: 24px 30px;
    border-bottom: 1px solid var(--border-color);
}

.modal-header h3 {
    font-size: 1.35rem;
    font-weight: 600;
}

.modal-close {
    background: none;
    border: none;
    color: var(--text-muted);
    cursor: pointer;
    transition: var(--transition-fast);
}

.modal-close:hover {
    color: var(--danger);
    transform: scale(1.1);
}

.modal-body {
    padding: 30px;
    overflow-y: auto;
    flex: 1;
}

.modal-footer {
    padding: 20px 30px;
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: flex-end;
    gap: 12px;
    background: rgba(0,0,0,0.02);
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

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

/* Grader split-pane */
.grader-container {
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: 24px;
    height: 100%;
}

.grader-file-pane {
    background: rgba(0,0,0,0.02);
    border: 1px dashed var(--border-color);
    border-radius: var(--radius-sm);
    padding: 20px;
    height: 400px;
    overflow-y: auto;
}

.grader-form-pane {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

/* File Upload drag/drop simulator UI */
.file-upload-zone {
    border: 2px dashed var(--border-color);
    border-radius: var(--radius-sm);
    padding: 40px 20px;
    text-align: center;
    cursor: pointer;
    transition: var(--transition);
    position: relative;
}

.file-upload-zone:hover {
    border-color: var(--primary);
    background: rgba(99, 102, 241, 0.02);
}

.file-upload-zone input[type="file"] {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    cursor: pointer;
}

.file-upload-zone svg {
    width: 48px;
    height: 48px;
    color: var(--text-muted);
    margin-bottom: 12px;
}

.file-upload-text {
    font-size: 0.95rem;
    color: var(--text-main);
    margin-bottom: 6px;
}

.file-upload-subtext {
    font-size: 0.8rem;
    color: var(--text-muted);
}

.file-upload-success-preview {
    margin-top: 15px;
    padding: 10px;
    background: rgba(16, 185, 129, 0.08);
    border: 1px solid rgba(16, 185, 129, 0.2);
    border-radius: var(--radius-sm);
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: var(--success);
    font-size: 0.85rem;
}

/* Chart Canvas & SVG Container */
.chart-container {
    width: 100%;
    height: 380px;
    padding: 20px;
    position: relative;
    overflow: hidden;
}

.chart-svg {
    width: 100%;
    height: 100%;
    overflow: visible;
}

/* SVG Chart styles */
.chart-grid-line {
    stroke: rgba(0, 0, 0, 0.04);
    stroke-width: 1;
}

.chart-axis-line {
    stroke: rgba(0, 0, 0, 0.08);
    stroke-width: 1;
}

.chart-axis-text {
    fill: var(--text-muted);
    font-size: 11px;
    font-family: inherit;
}

.chart-path {
    fill: none;
    stroke-width: 3.5;
    stroke-linecap: round;
    stroke-linejoin: round;
    transition: stroke-dashoffset 2s ease-in-out;
}

.chart-point {
    stroke-width: 3;
    cursor: pointer;
    transition: var(--transition-fast);
}

.chart-point:hover {
    r: 7px !important;
}

.chart-label-bg {
    fill: rgba(15, 23, 42, 0.9);
    stroke: var(--border-color);
    stroke-width: 1;
    rx: 4;
}

.chart-label-text {
    fill: var(--text-main);
    font-size: 11px;
    font-weight: 600;
}

.chart-legend {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    margin-top: 16px;
    justify-content: center;
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 0.85rem;
    color: var(--text-muted);
    cursor: pointer;
}

.legend-color-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
}

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

.empty-state svg {
    width: 54px;
    height: 54px;
    stroke-width: 1.5;
    margin-bottom: 16px;
    color: rgba(255, 255, 255, 0.15);
}

.empty-state p {
    font-size: 0.95rem;
}

/* File Viewer UI text rendering block */
.file-text-preview {
    font-family: monospace;
    white-space: pre-wrap;
    background: #f1f5f9;
    color: #0f172a;
    padding: 20px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-color);
    font-size: 0.85rem;
    line-height: 1.6;
    height: 100%;
}

.pdf-simulation-card {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 40px;
    background: rgba(0, 0, 0, 0.02);
    border-radius: var(--radius-sm);
    border: 1px solid var(--border-color);
    height: 100%;
}

.pdf-simulation-card svg {
    width: 64px;
    height: 64px;
    color: var(--danger);
    margin-bottom: 16px;
}

.pdf-simulation-card h4 {
    font-size: 1.2rem;
    margin-bottom: 8px;
}

.pdf-simulation-card p {
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-bottom: 20px;
}

/* Responsive Overrides */
@media (max-width: 1024px) {
    .grid-3col {
        grid-template-columns: 1fr;
    }
    .grid-2col {
        grid-template-columns: 1fr;
    }
    .grader-container {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .dashboard-wrapper {
        flex-direction: column;
    }
    .sidebar {
        width: 100%;
        height: auto;
        border-right: none;
        border-bottom: 1px solid var(--border-color);
    }
    .top-bar {
        padding: 20px;
    }
    .content-pane {
        padding: 20px;
    }
    .auth-card {
        padding: 24px;
    }
}