/* =========================================================
   Udemy Vault — Dashboard Styles
   Dark theme with glassmorphism, gradients, micro-animations
   ========================================================= */

:root {
    --bg-primary: #0a0e1a;
    --bg-secondary: #111827;
    --bg-card: rgba(17, 24, 39, 0.8);
    --bg-card-hover: rgba(30, 41, 59, 0.9);
    --border: rgba(255, 255, 255, 0.06);
    --border-hover: rgba(255, 255, 255, 0.12);
    --text-primary: #f1f5f9;
    --text-secondary: #94a3b8;
    --text-muted: #64748b;
    --purple: #a855f7;
    --purple-light: #c084fc;
    --purple-glow: rgba(168, 85, 247, 0.15);
    --pink: #ec4899;
    --blue: #3b82f6;
    --green: #22c55e;
    --amber: #f59e0b;
    --red: #ef4444;
    --radius: 16px;
    --radius-sm: 10px;
    --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
}

/* Subtle animated background gradient */
body::before {
    content: '';
    position: fixed;
    inset: 0;
    background:
        radial-gradient(ellipse 80% 50% at 50% -20%, rgba(168, 85, 247, 0.08), transparent),
        radial-gradient(ellipse 60% 40% at 80% 60%, rgba(59, 130, 246, 0.05), transparent);
    pointer-events: none;
    z-index: 0;
}

/* ---- Header ---- */
header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(10, 14, 26, 0.85);
    backdrop-filter: blur(20px) saturate(1.2);
    border-bottom: 1px solid var(--border);
    padding: 0 2rem;
}

.header-inner {
    max-width: 1400px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.logo-group {
    display: flex;
    align-items: center;
    gap: 14px;
}

.logo-icon {
    width: 40px;
    height: 40px;
    background: linear-gradient(135deg, var(--purple), var(--pink));
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
}

.logo-icon svg {
    width: 22px;
    height: 22px;
}

.logo-text {
    font-size: 1.35rem;
    font-weight: 800;
    background: linear-gradient(135deg, var(--purple-light), var(--pink));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: -0.02em;
}

.logo-sub {
    font-size: 0.75rem;
    color: var(--text-muted);
    font-weight: 400;
    letter-spacing: 0.02em;
}

/* ---- Buttons ---- */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    border-radius: var(--radius-sm);
    font-family: inherit;
    font-size: 0.875rem;
    font-weight: 600;
    cursor: pointer;
    border: none;
    transition: all var(--transition);
    white-space: nowrap;
}

.btn-primary {
    background: linear-gradient(135deg, var(--purple), var(--pink));
    color: white;
    box-shadow: 0 4px 20px rgba(168, 85, 247, 0.3);
}

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 8px 30px rgba(168, 85, 247, 0.4);
}

.btn-primary:active {
    transform: translateY(0);
}

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

.btn-ghost:hover {
    background: rgba(255, 255, 255, 0.05);
    color: var(--text-primary);
}

.btn-lg {
    padding: 12px 28px;
    font-size: 0.95rem;
}

.btn-spinner {
    animation: spin 0.8s linear infinite;
}

.hidden {
    display: none !important;
}

/* ---- Stats ---- */
#stats-section {
    max-width: 1400px;
    margin: 2rem auto;
    padding: 0 2rem;
    position: relative;
    z-index: 1;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1rem;
}

.stat-card {
    background: var(--bg-card);
    backdrop-filter: blur(12px);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 1.5rem;
    position: relative;
    overflow: hidden;
    transition: all var(--transition);
}

.stat-card:hover {
    border-color: var(--border-hover);
    transform: translateY(-2px);
}

.stat-glow {
    position: absolute;
    top: -20px;
    right: -20px;
    width: 80px;
    height: 80px;
    border-radius: 50%;
    filter: blur(30px);
    opacity: 0.5;
    transition: opacity var(--transition);
}

.stat-card:hover .stat-glow {
    opacity: 0.8;
}

.glow-purple { background: var(--purple); }
.glow-amber { background: var(--amber); }
.glow-blue { background: var(--blue); }
.glow-green { background: var(--green); }

.stat-label {
    display: block;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: 8px;
}

.stat-value {
    display: block;
    font-size: 2rem;
    font-weight: 800;
    letter-spacing: -0.03em;
    color: var(--text-primary);
}

/* ---- Controls ---- */
#controls-section {
    max-width: 1400px;
    margin: 0 auto 1.5rem;
    padding: 0 2rem;
    position: relative;
    z-index: 1;
}

.controls-bar {
    display: flex;
    align-items: center;
    gap: 12px;
    flex-wrap: wrap;
}

.search-box {
    flex: 1;
    min-width: 260px;
    position: relative;
}

.search-icon {
    position: absolute;
    left: 14px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
    pointer-events: none;
}

#search-input {
    width: 100%;
    padding: 12px 14px 12px 44px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    background: var(--bg-card);
    color: var(--text-primary);
    font-family: inherit;
    font-size: 0.9rem;
    outline: none;
    transition: all var(--transition);
}

#search-input:focus {
    border-color: var(--purple);
    box-shadow: 0 0 0 3px var(--purple-glow);
}

#search-input::placeholder {
    color: var(--text-muted);
}

.select-control {
    padding: 12px 16px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    background: var(--bg-card);
    color: var(--text-primary);
    font-family: inherit;
    font-size: 0.875rem;
    outline: none;
    cursor: pointer;
    transition: all var(--transition);
    -webkit-appearance: none;
    appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 24 24' fill='none' stroke='%2394a3b8' stroke-width='2'%3E%3Cpath d='m6 9 6 6 6-6'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 12px center;
    padding-right: 36px;
}

.select-control option {
    background: var(--bg-secondary);
    color: var(--text-primary);
}

.select-control:focus {
    border-color: var(--purple);
    box-shadow: 0 0 0 3px var(--purple-glow);
}

.toggle-label {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    user-select: none;
    padding: 10px 0;
}

.toggle-label input[type="checkbox"] {
    width: 18px;
    height: 18px;
    accent-color: var(--purple);
    cursor: pointer;
}

.toggle-text {
    font-size: 0.85rem;
    color: var(--text-secondary);
    white-space: nowrap;
}

.results-count {
    margin-top: 8px;
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* ---- Course Grid ---- */
.course-grid {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 2rem 4rem;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(340px, 1fr));
    gap: 1rem;
    position: relative;
    z-index: 1;
}

.course-card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    overflow: hidden;
    transition: all var(--transition);
    display: flex;
    flex-direction: column;
    animation: fadeInUp 0.4s ease forwards;
    opacity: 0;
}

.course-card:hover {
    border-color: var(--border-hover);
    transform: translateY(-3px);
    box-shadow: 0 12px 40px rgba(0, 0, 0, 0.4);
}

.course-thumb {
    width: 100%;
    aspect-ratio: 480 / 270;
    object-fit: cover;
    background: var(--bg-secondary);
    display: block;
}

.course-body {
    padding: 1.1rem;
    flex: 1;
    display: flex;
    flex-direction: column;
}

.course-title {
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--text-primary);
    line-height: 1.35;
    margin-bottom: 6px;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.course-title a {
    color: inherit;
    text-decoration: none;
    transition: color var(--transition);
}

.course-title a:hover {
    color: var(--purple-light);
}

.course-headline {
    font-size: 0.8rem;
    color: var(--text-muted);
    line-height: 1.4;
    margin-bottom: 10px;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    flex: 1;
}

.course-meta {
    display: flex;
    align-items: center;
    gap: 12px;
    flex-wrap: wrap;
    margin-bottom: 8px;
}

.meta-item {
    display: flex;
    align-items: center;
    gap: 4px;
    font-size: 0.75rem;
    color: var(--text-secondary);
}

.meta-item svg {
    width: 14px;
    height: 14px;
    opacity: 0.7;
}

.rating-stars {
    color: var(--amber);
    font-weight: 700;
}

.course-category {
    display: inline-block;
    background: rgba(168, 85, 247, 0.1);
    color: var(--purple-light);
    font-size: 0.7rem;
    font-weight: 600;
    padding: 4px 10px;
    border-radius: 20px;
    border: 1px solid rgba(168, 85, 247, 0.15);
    margin-right: 6px;
}

.course-language {
    display: inline-block;
    background: rgba(59, 130, 246, 0.1);
    color: #93c5fd;
    font-size: 0.7rem;
    font-weight: 500;
    padding: 4px 10px;
    border-radius: 20px;
    border: 1px solid rgba(59, 130, 246, 0.15);
}

.course-footer {
    padding: 0.8rem 1.1rem;
    border-top: 1px solid var(--border);
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.ai-badge {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 0.75rem;
    font-weight: 600;
}

.ai-score {
    background: linear-gradient(135deg, var(--purple), var(--pink));
    color: white;
    padding: 3px 10px;
    border-radius: 20px;
    font-size: 0.7rem;
    font-weight: 700;
}

.ai-rank-num {
    color: var(--text-muted);
    font-size: 0.75rem;
}

.ai-reason {
    font-size: 0.72rem;
    color: var(--text-secondary);
    font-style: italic;
    max-width: 200px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.unranked-badge {
    font-size: 0.72rem;
    color: var(--text-muted);
    font-style: italic;
}

/* ---- Modal ---- */
.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.7);
    backdrop-filter: blur(6px);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 200;
    padding: 2rem;
}

.modal-overlay.active {
    display: flex;
    animation: fadeIn 0.2s ease;
}

.modal-card {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    width: 100%;
    max-width: 560px;
    box-shadow: 0 25px 80px rgba(0, 0, 0, 0.5);
}

.modal-header {
    padding: 1.5rem 1.5rem 0;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.modal-header h2 {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--text-primary);
}

.modal-header h2 svg {
    color: var(--amber);
}

.modal-close {
    background: none;
    border: none;
    color: var(--text-muted);
    font-size: 1.5rem;
    cursor: pointer;
    transition: color var(--transition);
    line-height: 1;
}

.modal-close:hover {
    color: var(--text-primary);
}

.modal-body {
    padding: 1.5rem;
}

.modal-label {
    display: block;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 8px;
}

.modal-textarea {
    width: 100%;
    padding: 12px 14px;
    border-radius: var(--radius-sm);
    border: 1px solid var(--border);
    background: var(--bg-card);
    color: var(--text-primary);
    font-family: inherit;
    font-size: 0.9rem;
    resize: vertical;
    outline: none;
    transition: all var(--transition);
}

.modal-textarea:focus {
    border-color: var(--purple);
    box-shadow: 0 0 0 3px var(--purple-glow);
}

.modal-textarea::placeholder {
    color: var(--text-muted);
}

.modal-options {
    margin-top: 12px;
}

.preset-goals {
    margin-top: 16px;
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
}

.preset-label {
    font-size: 0.78rem;
    color: var(--text-muted);
    font-weight: 500;
}

.preset-btn {
    padding: 6px 12px;
    border-radius: 20px;
    border: 1px solid var(--border);
    background: transparent;
    color: var(--text-secondary);
    font-family: inherit;
    font-size: 0.75rem;
    font-weight: 500;
    cursor: pointer;
    transition: all var(--transition);
}

.preset-btn:hover {
    background: var(--purple-glow);
    border-color: var(--purple);
    color: var(--purple-light);
}

.modal-footer {
    padding: 0 1.5rem 1.5rem;
    display: flex;
    justify-content: flex-end;
    gap: 10px;
}

.rank-status {
    margin: 0 1.5rem 1.5rem;
    padding: 10px 14px;
    border-radius: var(--radius-sm);
    font-size: 0.85rem;
    font-weight: 500;
}

.rank-status.success {
    background: rgba(34, 197, 94, 0.1);
    border: 1px solid rgba(34, 197, 94, 0.2);
    color: var(--green);
}

.rank-status.error {
    background: rgba(239, 68, 68, 0.1);
    border: 1px solid rgba(239, 68, 68, 0.2);
    color: var(--red);
}

.rank-status.loading {
    background: rgba(59, 130, 246, 0.1);
    border: 1px solid rgba(59, 130, 246, 0.2);
    color: var(--blue);
}

/* ---- Loading ---- */
.loading-spinner {
    grid-column: 1 / -1;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 16px;
    padding: 4rem 0;
    color: var(--text-muted);
}

.spinner {
    width: 36px;
    height: 36px;
    border: 3px solid var(--border);
    border-top-color: var(--purple);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

/* ---- Animations ---- */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(16px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

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

/* ---- Responsive ---- */
@media (max-width: 900px) {
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .course-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 600px) {
    header { padding: 0 1rem; }
    #stats-section, #controls-section, .course-grid { padding-left: 1rem; padding-right: 1rem; }
    .stats-grid { grid-template-columns: 1fr 1fr; gap: 0.5rem; }
    .stat-value { font-size: 1.5rem; }
    .controls-bar { flex-direction: column; align-items: stretch; }
    .search-box { min-width: auto; }
}

/* ---- Scrollbar ---- */
::-webkit-scrollbar { width: 8px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: rgba(255, 255, 255, 0.08); border-radius: 4px; }
::-webkit-scrollbar-thumb:hover { background: rgba(255, 255, 255, 0.15); }

/* ---- Empty State ---- */
.empty-state {
    grid-column: 1 / -1;
    text-align: center;
    padding: 4rem 2rem;
    color: var(--text-muted);
}

.empty-state h3 {
    font-size: 1.2rem;
    margin-bottom: 8px;
    color: var(--text-secondary);
}