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

:root {
    --bg-primary: #0b0f19;
    --bg-surface: #111827;
    --bg-card: #161f30;
    --border-subtle: #1f293d;
    --border-focus: #3b82f6;
    --text-main: #f3f4f6;
    --text-muted: #9ca3af;
    --text-faint: #4b5563;
    --brand-blue: #3b82f6;
    --brand-blue-glow: rgba(59, 130, 246, 0.25);
    --success: #10b981;
    --success-bg: rgba(16, 185, 129, 0.15);
    --warning: #f59e0b;
    --warning-bg: rgba(245, 158, 11, 0.15);
    --danger: #ef4444;
    --danger-bg: rgba(239, 68, 68, 0.15);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-main);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

a {
    color: var(--brand-blue);
    text-decoration: none;
    transition: color 0.15s ease;
}

a:hover {
    color: #60a5fa;
}

/* Navigation */
.navbar {
    background-color: rgba(17, 24, 39, 0.85);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-subtle);
    padding: 0.85rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 50;
}

.brand {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-weight: 700;
    font-size: 1.15rem;
    color: #fff;
    letter-spacing: -0.02em;
}

.brand-badge {
    background: linear-gradient(135deg, #2563eb, #3b82f6);
    color: white;
    padding: 0.2rem 0.5rem;
    border-radius: 6px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.nav-link {
    color: var(--text-muted);
    font-size: 0.9rem;
    font-weight: 500;
    padding: 0.4rem 0.75rem;
    border-radius: 6px;
    transition: all 0.2s;
}

.nav-link:hover, .nav-link.active {
    color: #fff;
    background: var(--bg-card);
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    font-weight: 600;
    font-size: 0.875rem;
    padding: 0.55rem 1.15rem;
    border-radius: 8px;
    border: none;
    cursor: pointer;
    transition: all 0.2s ease;
    text-decoration: none;
}

.btn-primary {
    background: linear-gradient(135deg, #2563eb, #3b82f6);
    color: #fff;
    box-shadow: 0 4px 12px var(--brand-blue-glow);
}

.btn-primary:hover {
    background: linear-gradient(135deg, #1d4ed8, #2563eb);
    transform: translateY(-1px);
    color: #fff;
}

.btn-secondary {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    color: var(--text-main);
}

.btn-secondary:hover {
    background: #1f2d47;
    border-color: #374151;
}

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

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

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

/* Container */
.container {
    max-width: 1200px;
    margin: 2rem auto;
    padding: 0 1.5rem;
    flex: 1;
    width: 100%;
}

/* Cards */
.card {
    background: var(--bg-surface);
    border: 1px solid var(--border-subtle);
    border-radius: 12px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
}

/* KPI Grid */
.kpi-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1.25rem;
    margin-bottom: 2rem;
}

.kpi-card {
    background: var(--bg-surface);
    border: 1px solid var(--border-subtle);
    border-radius: 12px;
    padding: 1.25rem;
    display: flex;
    flex-direction: column;
}

.kpi-title {
    font-size: 0.8rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    font-weight: 600;
}

.kpi-val {
    font-size: 2rem;
    font-weight: 800;
    margin-top: 0.4rem;
    color: #fff;
}

/* Course Grid */
.course-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 1.5rem;
}

.course-card {
    background: var(--bg-surface);
    border: 1px solid var(--border-subtle);
    border-radius: 12px;
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    transition: transform 0.2s, border-color 0.2s;
}

.course-card:hover {
    transform: translateY(-2px);
    border-color: #2e3c54;
}

.badge {
    display: inline-block;
    padding: 0.25rem 0.65rem;
    border-radius: 9999px;
    font-size: 0.75rem;
    font-weight: 600;
}

.badge-success { background: var(--success-bg); color: #34d399; border: 1px solid rgba(52, 211, 153, 0.3); }
.badge-warning { background: var(--warning-bg); color: #fbbf24; border: 1px solid rgba(251, 191, 36, 0.3); }
.badge-danger  { background: var(--danger-bg);  color: #f87171; border: 1px solid rgba(248, 113, 113, 0.3); }

/* Progress Bar */
.progress-bar-container {
    background: #1f2937;
    border-radius: 9999px;
    height: 8px;
    width: 100%;
    margin: 0.75rem 0;
    overflow: hidden;
}

.progress-bar-fill {
    height: 100%;
    background: linear-gradient(90deg, #3b82f6, #10b981);
    border-radius: 9999px;
    transition: width 0.3s ease;
}

/* Table */
.data-table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 1rem;
    font-size: 0.875rem;
}

.data-table th {
    text-align: left;
    padding: 0.85rem 1rem;
    background: #0f1523;
    color: var(--text-muted);
    font-weight: 600;
    border-bottom: 1px solid var(--border-subtle);
}

.data-table td {
    padding: 1rem;
    border-bottom: 1px solid #1a2233;
}

.data-table tr:hover td {
    background: #151d2e;
}

/* Markdown Reader */
.markdown-body {
    line-height: 1.8;
    font-size: 1.05rem;
    color: #e5e7eb;
}

.markdown-body h1 { font-size: 1.85rem; margin-bottom: 1rem; color: #fff; border-bottom: 1px solid var(--border-subtle); padding-bottom: 0.5rem; }
.markdown-body h2 { font-size: 1.45rem; margin: 1.5rem 0 0.75rem; color: #f3f4f6; }
.markdown-body h3 { font-size: 1.2rem; margin: 1.25rem 0 0.5rem; color: #d1d5db; }
.markdown-body p  { margin-bottom: 1.25rem; }
.markdown-body ul, .markdown-body ol { margin-left: 1.5rem; margin-bottom: 1.25rem; }
.markdown-body li { margin-bottom: 0.5rem; }
.markdown-body code { background: #1e293b; padding: 0.2rem 0.4rem; border-radius: 4px; font-size: 0.9em; }
.markdown-body pre { background: #0f172a; padding: 1rem; border-radius: 8px; overflow-x: auto; margin-bottom: 1.25rem; border: 1px solid #1e293b; }

/* Messages */
.alert {
    padding: 0.85rem 1.25rem;
    border-radius: 8px;
    margin-bottom: 1.5rem;
    font-size: 0.9rem;
}
.alert-success { background: var(--success-bg); border: 1px solid #059669; color: #a7f3d0; }
.alert-error   { background: var(--danger-bg);  border: 1px solid #dc2626; color: #fecaca; }
.alert-info    { background: rgba(59, 130, 246, 0.15); border: 1px solid #2563eb; color: #bfdbfe; }