/* DotScroll - AI Learning Feed Styles */

:root {
    --color-bg: #0a0a0f;
    --color-surface: #12121a;
    --color-surface-hover: #1a1a25;
    --color-border: #2a2a3a;
    --color-text: #e8e8ed;
    --color-text-muted: #8888a0;
    --color-primary: #6366f1;
    --color-primary-hover: #818cf8;

    --color-claude: #d97706;
    --color-gpt: #10b981;
    --color-gemini: #3b82f6;

    --color-beginner: #22c55e;
    --color-intermediate: #eab308;
    --color-advanced: #f97316;
    --color-expert: #ef4444;

    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;

    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.5);
}

/* Base Layout */
body {
    background: var(--color-bg);
    color: var(--color-text);
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    margin: 0;
    padding: 0;
}

.feed-page {
    max-width: 680px;
    margin: 0 auto;
    padding: 20px;
    padding-bottom: 100px;
}

/* Header */
.feed-header {
    text-align: center;
    padding: 40px 0 30px;
    border-bottom: 1px solid var(--color-border);
    margin-bottom: 20px;
}

.feed-header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin: 0;
    background: linear-gradient(135deg, var(--color-claude), var(--color-gpt), var(--color-gemini));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.feed-header .tagline {
    color: var(--color-text-muted);
    margin: 8px 0 20px;
    font-size: 1rem;
}

/* Stats Bar */
.stats-bar {
    display: flex;
    justify-content: center;
    gap: 30px;
    padding: 15px 0;
}

.stats-bar .stat {
    text-align: center;
}

.stats-bar .stat-value {
    display: block;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-text);
}

.stats-bar .stat-value small {
    font-size: 0.8rem;
    font-weight: 400;
}

.stats-bar .stat-label {
    font-size: 0.75rem;
    color: var(--color-text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.stats-bar .stat.streak .stat-value {
    color: var(--color-claude);
}

/* Provider Tabs */
.provider-tabs {
    display: flex;
    justify-content: center;
    gap: 8px;
    padding: 20px 0;
    flex-wrap: wrap;
}

.provider-tab {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 10px 18px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    background: var(--color-surface);
    color: var(--color-text-muted);
    cursor: pointer;
    transition: all 0.2s;
    font-size: 0.9rem;
}

.provider-tab:hover {
    background: var(--color-surface-hover);
    color: var(--color-text);
}

.provider-tab.active {
    border-color: var(--color-primary);
    color: var(--color-text);
}

.provider-tab.claude.active {
    border-color: var(--color-claude);
    background: rgba(217, 119, 6, 0.1);
}

.provider-tab.gpt.active {
    border-color: var(--color-gpt);
    background: rgba(16, 185, 129, 0.1);
}

.provider-tab.gemini.active {
    border-color: var(--color-gemini);
    background: rgba(59, 130, 246, 0.1);
}

.provider-icon {
    font-size: 1rem;
}

/* Filter Bar */
.filter-bar {
    padding: 15px 0;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.filter-section {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    align-items: center;
}

.filter-section.categories {
    overflow-x: auto;
    padding-bottom: 5px;
    -webkit-overflow-scrolling: touch;
}

.filter-label {
    font-size: 0.8rem;
    color: var(--color-text-muted);
    margin-right: 4px;
}

.search-box {
    position: relative;
    flex: 1;
    min-width: 200px;
}

.search-box input {
    width: 100%;
    padding: 10px 35px 10px 14px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    background: var(--color-surface);
    color: var(--color-text);
    font-size: 0.9rem;
}

.search-box input:focus {
    outline: none;
    border-color: var(--color-primary);
}

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

.clear-search {
    position: absolute;
    right: 10px;
    top: 50%;
    transform: translateY(-50%);
    background: none;
    border: none;
    color: var(--color-text-muted);
    cursor: pointer;
    font-size: 1.2rem;
    padding: 0;
}

.filter-chip {
    padding: 6px 12px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    background: var(--color-surface);
    color: var(--color-text-muted);
    cursor: pointer;
    font-size: 0.8rem;
    transition: all 0.2s;
    white-space: nowrap;
}

.filter-chip:hover {
    background: var(--color-surface-hover);
    color: var(--color-text);
}

.filter-chip.active {
    background: var(--color-primary);
    border-color: var(--color-primary);
    color: white;
}

.filter-chip.difficulty-beginner.active { background: var(--color-beginner); border-color: var(--color-beginner); }
.filter-chip.difficulty-intermediate.active { background: var(--color-intermediate); border-color: var(--color-intermediate); color: #000; }
.filter-chip.difficulty-advanced.active { background: var(--color-advanced); border-color: var(--color-advanced); }
.filter-chip.difficulty-expert.active { background: var(--color-expert); border-color: var(--color-expert); }

.filter-section select {
    padding: 6px 12px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    background: var(--color-surface);
    color: var(--color-text);
    font-size: 0.8rem;
    cursor: pointer;
}

/* Infinite Scroll Container */
.infinite-scroll-container {
    margin-top: 20px;
}

.scroll-content {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

/* Learning Card */
.learning-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    transition: all 0.2s;
    cursor: pointer;
}

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

.learning-card.expanded {
    cursor: default;
}

.learning-card .card-header {
    padding: 20px;
}

.learning-card .card-meta {
    display: flex;
    gap: 8px;
    margin-bottom: 12px;
    flex-wrap: wrap;
}

.category-badge {
    padding: 4px 10px;
    background: var(--color-primary);
    color: white;
    border-radius: var(--radius-sm);
    font-size: 0.7rem;
    text-transform: uppercase;
    font-weight: 600;
    letter-spacing: 0.5px;
}

.difficulty-badge {
    padding: 4px 10px;
    border-radius: var(--radius-sm);
    font-size: 0.7rem;
    text-transform: uppercase;
    font-weight: 600;
}

.difficulty-beginner .difficulty-badge { background: var(--color-beginner); color: white; }
.difficulty-intermediate .difficulty-badge { background: var(--color-intermediate); color: #000; }
.difficulty-advanced .difficulty-badge { background: var(--color-advanced); color: white; }
.difficulty-expert .difficulty-badge { background: var(--color-expert); color: white; }

.read-time {
    padding: 4px 10px;
    background: var(--color-surface-hover);
    color: var(--color-text-muted);
    border-radius: var(--radius-sm);
    font-size: 0.7rem;
}

.card-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin: 0 0 10px;
    line-height: 1.4;
    color: var(--color-text);
}

.card-summary {
    color: var(--color-text-muted);
    font-size: 0.95rem;
    margin: 0 0 12px;
    line-height: 1.6;
}

.card-footer-meta {
    display: flex;
    gap: 12px;
    font-size: 0.8rem;
    color: var(--color-text-muted);
}

.card-footer-meta .source {
    font-weight: 500;
    color: var(--color-primary);
}

/* Expanded Card Content */
.card-content {
    padding: 0 20px 20px;
    border-top: 1px solid var(--color-border);
    margin-top: 10px;
    padding-top: 20px;
}

.content-body {
    color: var(--color-text);
    line-height: 1.8;
    font-size: 0.95rem;
}

.content-body p {
    margin: 0 0 16px;
}

.card-actions {
    display: flex;
    gap: 10px;
    margin-top: 20px;
    padding-top: 15px;
    border-top: 1px solid var(--color-border);
}

.action-btn {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 8px 14px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-sm);
    background: var(--color-surface);
    color: var(--color-text-muted);
    cursor: pointer;
    font-size: 0.85rem;
    text-decoration: none;
    transition: all 0.2s;
}

.action-btn:hover {
    background: var(--color-surface-hover);
    color: var(--color-text);
    border-color: var(--color-primary);
}

.action-btn.active {
    background: var(--color-claude);
    border-color: var(--color-claude);
    color: white;
}

.action-btn .icon {
    font-size: 1rem;
}

/* Tags */
.card-tags {
    display: flex;
    gap: 6px;
    padding: 12px 20px;
    background: rgba(0, 0, 0, 0.2);
    flex-wrap: wrap;
}

.tag {
    padding: 4px 10px;
    background: var(--color-surface-hover);
    color: var(--color-text-muted);
    border-radius: var(--radius-sm);
    font-size: 0.75rem;
}

/* Loading */
.loading-indicator {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 15px;
    padding: 40px;
    color: var(--color-text-muted);
}

.spinner {
    width: 40px;
    height: 40px;
    border: 3px solid var(--color-border);
    border-top-color: var(--color-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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

.end-message {
    text-align: center;
    padding: 40px;
    color: var(--color-text-muted);
    font-size: 0.9rem;
}

/* Back to Top */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    padding: 12px 20px;
    background: var(--color-primary);
    color: white;
    border: none;
    border-radius: var(--radius-lg);
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 600;
    box-shadow: var(--shadow-lg);
    opacity: 0;
    visibility: hidden;
    transition: all 0.3s;
    z-index: 1000;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    background: var(--color-primary-hover);
    transform: translateY(-2px);
}

/* Modal */
.modal-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    padding: 20px;
}

.note-modal {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: 24px;
    max-width: 500px;
    width: 100%;
    box-shadow: var(--shadow-lg);
}

.note-modal h3 {
    margin: 0 0 16px;
    font-size: 1.25rem;
}

.note-modal textarea {
    width: 100%;
    min-height: 150px;
    padding: 12px;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    background: var(--color-bg);
    color: var(--color-text);
    font-size: 0.95rem;
    resize: vertical;
    font-family: inherit;
}

.note-modal textarea:focus {
    outline: none;
    border-color: var(--color-primary);
}

.modal-actions {
    display: flex;
    gap: 10px;
    justify-content: flex-end;
    margin-top: 16px;
}

.btn-primary, .btn-secondary {
    padding: 10px 20px;
    border-radius: var(--radius-md);
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-primary {
    background: var(--color-primary);
    color: white;
    border: none;
}

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

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

.btn-secondary:hover {
    background: var(--color-surface-hover);
}

/* Responsive */
@media (max-width: 600px) {
    .feed-page {
        padding: 15px;
    }

    .feed-header h1 {
        font-size: 2rem;
    }

    .stats-bar {
        gap: 20px;
    }

    .stats-bar .stat-value {
        font-size: 1.25rem;
    }

    .provider-tabs {
        gap: 6px;
    }

    .provider-tab {
        padding: 8px 14px;
        font-size: 0.85rem;
    }

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

    .back-to-top {
        bottom: 20px;
        right: 20px;
    }
}

/* Load More Button */
.load-more-btn {
    display: block;
    width: 100%;
    padding: 16px;
    margin: 20px 0;
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    color: var(--color-text);
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

.load-more-btn:hover {
    background: var(--color-primary);
    border-color: var(--color-primary);
}

/* Scroll sentinel (invisible) */
.scroll-sentinel {
    height: 1px;
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: var(--color-text-muted);
}

.empty-state .empty-icon {
    font-size: 4rem;
    margin-bottom: 20px;
}

.empty-state h3 {
    color: var(--color-text);
    font-size: 1.5rem;
    margin: 0 0 10px;
}

.empty-state p {
    margin: 0 0 20px;
    font-size: 1rem;
}

.empty-state .btn-primary {
    display: inline-block;
}