/**
 * Feed Design System V2 - Refined Styling
 *
 * Modern feed design with:
 * - Full screen width minus 6px (prevents content shift on scroll)
 * - Redesigned filter/privacy UI with integrated visual hierarchy
 * - Smooth transitions and modern interactions
 * - Optimized typography and spacing
 */

/* ===== Root Variables ===== */

:root {
    --feed-width: calc(100vw - 6px);
    --feed-max-width: 1200px;
    --card-gutter: 6px;
    --filter-height: 56px;
    --privacy-height: 48px;
}

/* ===== Main Feed Wrapper ===== */

.feed-design-wrapper {
    width: var(--feed-width);
    height: 100%;
    display: flex;
    flex-direction: column;
    background: var(--bg-primary, #ffffff);
    overflow: hidden;
    margin: 0 auto;
    box-sizing: border-box;
}

.feed-wrapper {
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
    background: inherit;
}

/* ===== Top Bar (Filters + Privacy) ===== */

.feed-top-bar {
    flex-shrink: 0;
    display: flex;
    flex-direction: column;
    background: var(--bg-primary, #ffffff);
    border-bottom: 1px solid var(--border-color, #e5e7eb);
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.05);
    z-index: 100;
}

/* ===== Filter Bar (Content Types) ===== */

.feed-filter-bar {
    flex-shrink: 0;
    display: flex;
    align-items: center;
    gap: var(--spacing-2, 8px);
    padding: var(--spacing-2, 8px) var(--spacing-3, 12px);
    height: var(--filter-height);
    background: var(--bg-primary, #ffffff);
    border-bottom: 1px solid var(--border-color, #e5e7eb);
    overflow-x: auto;
    overflow-y: hidden;
    scrollbar-width: thin;
    scrollbar-color: rgba(0, 0, 0, 0.08) transparent;
    -webkit-overflow-scrolling: touch;
}

.feed-filter-bar::-webkit-scrollbar {
    height: 3px;
}

.feed-filter-bar::-webkit-scrollbar-track {
    background: transparent;
}

.feed-filter-bar::-webkit-scrollbar-thumb {
    background: rgba(0, 0, 0, 0.08);
    border-radius: 2px;
}

.feed-filter-bar::-webkit-scrollbar-thumb:hover {
    background: rgba(0, 0, 0, 0.12);
}

/* ===== Filter Tabs (Content Types) ===== */

.feed-filter-tab,
.feed-status-btn {
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-1, 4px);
    height: 40px;
    padding: 0 var(--spacing-2, 8px);
    border: none;
    border-radius: var(--radius-full, 20px);
    background: var(--bg-tertiary, #f3f4f6);
    color: var(--text-secondary, #6b7280);
    font-size: 0.85rem;
    font-weight: 500;
    white-space: nowrap;
    cursor: pointer;
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    user-select: none;
    border: 1px solid transparent;
}

.feed-filter-tab:hover,
.feed-status-btn:hover {
    background: var(--bg-secondary, #f0f1f3);
    color: var(--text-primary, #111827);
    border-color: var(--border-color, #e5e7eb);
}

.feed-filter-tab.active {
    background: var(--color-primary, #3b82f6);
    color: white;
    box-shadow: 0 2px 8px rgba(59, 130, 246, 0.25), inset 0 1px 0 rgba(255, 255, 255, 0.3);
    border-color: var(--color-primary, #3b82f6);
}

.feed-filter-tab.active:hover {
    background: var(--color-primary-dark, #2563eb);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.35), inset 0 1px 0 rgba(255, 255, 255, 0.3);
}

.feed-filter-tab i,
.feed-status-btn i {
    font-size: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Filter Badge */
.filter-badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 22px;
    height: 22px;
    padding: 0 6px;
    background: rgba(0, 0, 0, 0.08);
    border-radius: 11px;
    font-size: 0.7rem;
    font-weight: 700;
    letter-spacing: 0.3px;
    transition: all 0.2s ease;
    margin-left: 2px;
}

.feed-filter-tab.active .filter-badge {
    background: rgba(255, 255, 255, 0.25);
    color: white;
}

.feed-status-filters {
    display: flex;
    gap: var(--spacing-2, 8px);
    margin-left: auto;
    padding-right: var(--spacing-1, 4px);
}

/* ===== Privacy Filter Bar ===== */

.feed-privacy-bar {
    flex-shrink: 0;
    display: flex;
    align-items: center;
    gap: var(--spacing-1, 4px);
    padding: var(--spacing-1, 4px) var(--spacing-3, 12px);
    height: var(--privacy-height);
    background: var(--bg-tertiary, #f3f4f6);
    border-bottom: 1px solid var(--border-color, #e5e7eb);
    overflow-x: auto;
    overflow-y: hidden;
    scrollbar-width: thin;
    -webkit-overflow-scrolling: touch;
}

.feed-privacy-bar::-webkit-scrollbar {
    height: 2px;
}

.feed-privacy-bar::-webkit-scrollbar-track {
    background: transparent;
}

.feed-privacy-bar::-webkit-scrollbar-thumb {
    background: rgba(0, 0, 0, 0.08);
    border-radius: 1px;
}

/* Privacy Filter Buttons */
.feed-privacy-btn {
    flex-shrink: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-1, 4px);
    height: 36px;
    padding: 0 var(--spacing-2, 8px);
    border: 1px solid var(--border-color, #d1d5db);
    border-radius: var(--radius-md, 8px);
    background: var(--bg-card, white);
    color: var(--text-secondary, #6b7280);
    font-size: 0.8rem;
    font-weight: 500;
    white-space: nowrap;
    cursor: pointer;
    transition: all 0.15s ease;
    position: relative;
    user-select: none;
}

.feed-privacy-btn:hover {
    border-color: var(--color-primary, #3b82f6);
    background: rgba(59, 130, 246, 0.04);
    color: var(--color-primary, #3b82f6);
    box-shadow: 0 1px 3px rgba(59, 130, 246, 0.1);
}

.feed-privacy-btn.active {
    border-color: var(--color-primary, #3b82f6);
    background: var(--color-primary, #3b82f6);
    color: white;
    box-shadow: 0 2px 6px rgba(59, 130, 246, 0.25);
}

.feed-privacy-btn i {
    font-size: 0.875rem;
}

.privacy-label {
    display: inline;
    font-size: 0.8rem;
}

/* Privacy level hover indicators */
.feed-privacy-btn[data-privacy="public"]:not(.active):hover {
    border-color: #10b981;
    color: #10b981;
}

.feed-privacy-btn[data-privacy="friends"]:not(.active):hover {
    border-color: #3b82f6;
    color: #3b82f6;
}

.feed-privacy-btn[data-privacy="followers"]:not(.active):hover {
    border-color: #0ea5e9;
    color: #0ea5e9;
}

.feed-privacy-btn[data-privacy="private"]:not(.active):hover {
    border-color: #f59e0b;
    color: #f59e0b;
}

/* ===== Content Container (Scrollable with Dynamic Stretching) ===== */

.feed-content-container {
    flex: 1;
    overflow-y: auto;
    overflow-x: hidden;
    scroll-behavior: smooth;
    -webkit-overflow-scrolling: touch;
    background: var(--bg-primary, #ffffff);
}

/* Scrollbar styling */
.feed-content-container::-webkit-scrollbar {
    width: 8px;
}

.feed-content-container::-webkit-scrollbar-track {
    background: transparent;
}

.feed-content-container::-webkit-scrollbar-thumb {
    background: rgba(0, 0, 0, 0.12);
    border-radius: 4px;
}

.feed-content-container::-webkit-scrollbar-thumb:hover {
    background: rgba(0, 0, 0, 0.2);
}

/* ===== Content List (Stretchable) ===== */

.feed-content-list {
    display: flex;
    flex-direction: column;
    gap: var(--card-gutter);
    padding: var(--card-gutter);
    /* Dynamic stretching via JavaScript scaleY transform */
    transition: transform 0.06s linear;
}

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

.feed-content-card {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-2, 8px);
    padding: var(--spacing-3, 12px);
    background: var(--bg-card, white);
    border: 1px solid var(--border-color, #e5e7eb);
    border-radius: var(--radius-lg, 12px);
    transition: all 0.2s cubic-bezier(0.4, 0, 0.2, 1);
    cursor: pointer;
    position: relative;
    overflow: hidden;
}

.feed-content-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 0;
    background: var(--color-primary, #3b82f6);
    opacity: 0;
    transition: opacity 0.3s ease, height 0.3s ease;
}

.feed-content-card:hover {
    border-color: var(--color-primary, #3b82f6);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.15);
}

.feed-content-card:hover::before {
    opacity: 0.08;
    height: 3px;
}

/* Unread card styling */
.feed-content-card.unread {
    background: linear-gradient(135deg, rgba(59, 130, 246, 0.03) 0%, rgba(59, 130, 246, 0.01) 100%);
    border: 1px solid rgba(59, 130, 246, 0.2);
    border-left: 3px solid var(--color-primary, #3b82f6);
}

.feed-content-card.unread:hover {
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.2);
}

/* Read card styling */
.feed-content-card.read {
    opacity: 0.75;
}

.feed-content-card.read:hover {
    opacity: 1;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
}

/* Card header */
.feed-content-card .card-header {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-2, 8px);
    margin-bottom: var(--spacing-1, 4px);
}

.feed-content-card .card-title {
    margin: 0;
    font-size: 1.0625rem;
    font-weight: 600;
    color: var(--text-primary, #111827);
    flex: 1;
    letter-spacing: -0.3px;
}

.feed-content-card .card-body {
    color: var(--text-secondary, #6b7280);
    font-size: 0.95rem;
    line-height: 1.5;
    letter-spacing: 0.1px;
}

/* Card status chips container */
.card-status-chips {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-1, 4px);
    margin-top: var(--spacing-1, 4px);
    padding-top: var(--spacing-2, 8px);
    border-top: 1px solid var(--border-color, #e5e7eb);
    align-items: center;
}

/* Status chip styling */
.card-status-chips .status-chip {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 4px 8px;
    font-size: 0.75rem;
    font-weight: 500;
    border-radius: 4px;
    white-space: nowrap;
    background: rgba(0, 0, 0, 0.03);
    color: var(--text-secondary, #6b7280);
    border: 1px solid rgba(0, 0, 0, 0.06);
}

.card-status-chips .status-chip i {
    font-size: 0.75rem;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Status chip variants */
.card-status-chips .status-chip.status-unread {
    background: rgba(59, 130, 246, 0.1);
    color: #1e40af;
    border-color: rgba(59, 130, 246, 0.3);
}

.card-status-chips .status-chip.status-read {
    background: rgba(107, 114, 128, 0.08);
    color: #4b5563;
    border-color: rgba(107, 114, 128, 0.2);
}

.card-status-chips .status-chip.status-sent {
    background: rgba(251, 146, 60, 0.1);
    color: #b45309;
    border-color: rgba(251, 146, 60, 0.3);
}

.card-status-chips .status-chip.status-received {
    background: rgba(16, 185, 129, 0.1);
    color: #065f46;
    border-color: rgba(16, 185, 129, 0.3);
}

.card-status-chips .status-chip.status-unsent {
    background: rgba(239, 68, 68, 0.1);
    color: #7f1d1d;
    border-color: rgba(239, 68, 68, 0.3);
}

/* Status timestamp styling */
.card-status-chips .status-timestamp {
    display: inline-flex;
    align-items: center;
    font-size: 0.7rem;
    color: var(--text-secondary, #9ca3af);
    order: -1;
}

/* ===== Empty & Error States ===== */

.feed-empty-state,
.feed-error-state {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-3, 12px);
    padding: var(--spacing-6, 24px);
    min-height: 300px;
    text-align: center;
    color: var(--text-secondary, #6b7280);
}

.feed-empty-state .empty-icon,
.feed-error-state .error-icon {
    font-size: 4rem;
    opacity: 0.3;
}

.feed-empty-state .empty-message,
.feed-error-state .error-message {
    font-size: 1.0625rem;
    line-height: 1.6;
    max-width: 340px;
    letter-spacing: 0.2px;
}

.feed-error-state {
    color: var(--error-color, #ef4444);
}

.feed-error-state .error-icon {
    color: var(--error-color, #ef4444);
}

/* ===== Sentinel (Infinite Scroll Trigger) ===== */

.feed-sentinel {
    height: 2px;
    margin: var(--spacing-4, 16px) 0;
    pointer-events: none;
}

/* ===== Loading State ===== */

.feed-loading {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-2, 8px);
    padding: var(--spacing-4, 16px);
}

.feed-loading-spinner {
    width: 20px;
    height: 20px;
    border: 2px solid rgba(59, 130, 246, 0.2);
    border-top-color: var(--color-primary, #3b82f6);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

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

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

/* Tablet (768px and below) */
@media (max-width: 768px) {
    :root {
        --filter-height: 48px;
        --privacy-height: 40px;
    }

    .feed-filter-bar {
        gap: var(--spacing-1, 4px);
    }

    .feed-filter-tab,
    .feed-status-btn {
        height: 36px;
        padding: 0 var(--spacing-1, 4px);
        font-size: 0.75rem;
    }

    .feed-filter-tab i,
    .feed-status-btn i {
        font-size: 0.875rem;
    }

    .feed-filter-tab span:not(.filter-badge),
    .feed-status-btn span:not(.filter-badge) {
        display: none;
    }

    .filter-badge {
        min-width: 20px;
        height: 20px;
        font-size: 0.65rem;
        padding: 0 4px;
    }

    .feed-privacy-bar {
        gap: 0;
        padding: var(--spacing-1, 4px) var(--spacing-2, 8px);
    }

    .feed-privacy-btn {
        height: 32px;
        padding: 0 var(--spacing-1, 4px);
        font-size: 0.7rem;
    }

    .feed-privacy-btn i {
        font-size: 0.875rem;
    }

    .privacy-label {
        display: none;
    }

    .feed-content-card {
        padding: var(--spacing-2, 8px);
        gap: var(--spacing-1, 4px);
    }

    .feed-content-card .card-title {
        font-size: 1rem;
    }

    .feed-content-card .card-body {
        font-size: 0.9rem;
    }

    .card-status-chips {
        gap: 3px;
        margin-top: 4px;
        padding-top: 6px;
    }

    .card-status-chips .status-chip {
        padding: 3px 6px;
        font-size: 0.7rem;
    }
}

/* Mobile (480px and below) */
@media (max-width: 480px) {
    :root {
        --feed-width: calc(100vw - 6px);
        --filter-height: 44px;
        --privacy-height: 36px;
        --card-gutter: 4px;
    }

    .feed-filter-bar {
        padding: var(--spacing-1, 4px) 0;
        gap: 0;
        height: var(--filter-height);
    }

    .feed-filter-tab,
    .feed-status-btn {
        height: 32px;
        padding: 0 var(--spacing-1, 4px);
        font-size: 0.65rem;
        flex: 1;
        border-radius: var(--radius-md, 8px);
    }

    .feed-status-filters {
        display: none;
    }

    .feed-privacy-bar {
        padding: var(--spacing-1, 4px) 0;
        gap: 0;
        height: var(--privacy-height);
    }

    .feed-privacy-btn {
        height: 28px;
        padding: 0;
        font-size: 0.65rem;
        flex: 1;
        border: none;
        border-radius: var(--radius-sm, 6px);
        justify-content: center;
    }

    .feed-privacy-btn i {
        font-size: 0.75rem;
    }

    .feed-content-list {
        padding: var(--card-gutter);
        gap: var(--card-gutter);
    }

    .feed-content-card {
        padding: var(--spacing-2, 8px);
        gap: var(--spacing-1, 4px);
        border-radius: 8px;
        margin: 0;
    }

    .feed-content-card .card-title {
        font-size: 0.9375rem;
        font-weight: 600;
    }

    .feed-content-card .card-body {
        font-size: 0.85rem;
        line-height: 1.4;
    }

    .feed-empty-state,
    .feed-error-state {
        padding: var(--spacing-4, 16px);
        min-height: 250px;
    }

    .feed-empty-state .empty-icon,
    .feed-error-state .error-icon {
        font-size: 3rem;
    }

    .feed-empty-state .empty-message,
    .feed-error-state .error-message {
        font-size: 1rem;
        max-width: 280px;
    }

    .card-status-chips {
        gap: 3px;
        margin-top: 4px;
        padding-top: 6px;
        border-top: none;
        flex-direction: row;
    }

    .card-status-chips .status-chip {
        padding: 2px 5px;
        font-size: 0.65rem;
        flex: 0 1 auto;
    }
}

/* ===== Dark Mode ===== */

@media (prefers-color-scheme: dark) {
    .feed-design-wrapper {
        background: var(--bg-primary, #0f0f1a);
    }

    .feed-top-bar {
        background: var(--bg-secondary, #1a1a2e);
        border-bottom-color: var(--border-color, #2a2a3e);
    }

    .feed-filter-bar {
        background: var(--bg-secondary, #1a1a2e);
        border-bottom-color: var(--border-color, #2a2a3e);
    }

    .feed-filter-tab,
    .feed-status-btn {
        background: var(--bg-tertiary, #252540);
        color: var(--text-secondary, #a0a0b0);
        border-color: var(--border-color, #2a2a3e);
    }

    .feed-filter-tab:hover,
    .feed-status-btn:hover {
        background: rgba(129, 140, 248, 0.1);
        color: var(--color-primary, #818cf8);
        border-color: var(--color-primary, #818cf8);
    }

    .feed-filter-tab.active {
        background: var(--color-primary, #818cf8);
        color: white;
        border-color: var(--color-primary, #818cf8);
        box-shadow: 0 2px 8px rgba(129, 140, 248, 0.35), inset 0 1px 0 rgba(255, 255, 255, 0.1);
    }

    .filter-badge {
        background: rgba(255, 255, 255, 0.08);
        color: var(--text-secondary, #a0a0b0);
    }

    .feed-filter-tab.active .filter-badge {
        background: rgba(255, 255, 255, 0.2);
        color: white;
    }

    .feed-privacy-bar {
        background: var(--bg-tertiary, #252540);
        border-bottom-color: var(--border-color, #2a2a3e);
    }

    .feed-privacy-btn {
        background: var(--bg-secondary, #1a1a2e);
        border-color: var(--border-color, #2a2a3e);
        color: var(--text-secondary, #a0a0b0);
    }

    .feed-privacy-btn:hover {
        border-color: var(--color-primary, #818cf8);
        background: rgba(129, 140, 248, 0.08);
        color: var(--color-primary, #818cf8);
        box-shadow: 0 1px 3px rgba(129, 140, 248, 0.15);
    }

    .feed-privacy-btn.active {
        border-color: var(--color-primary, #818cf8);
        background: var(--color-primary, #818cf8);
        color: white;
        box-shadow: 0 2px 6px rgba(129, 140, 248, 0.3);
    }

    .feed-content-container {
        background: var(--bg-primary, #0f0f1a);
    }

    .feed-content-card {
        background: var(--bg-card, #1a1a2e);
        border-color: var(--border-color, #2a2a3e);
    }

    .feed-content-card:hover {
        border-color: var(--color-primary, #818cf8);
        box-shadow: 0 4px 12px rgba(129, 140, 248, 0.2);
    }

    .feed-content-card.unread {
        background: linear-gradient(135deg, rgba(129, 140, 248, 0.05) 0%, rgba(129, 140, 248, 0.02) 100%);
        border-color: rgba(129, 140, 248, 0.25);
        border-left-color: var(--color-primary, #818cf8);
    }

    .feed-content-card.unread:hover {
        box-shadow: 0 4px 12px rgba(129, 140, 248, 0.25);
    }

    .feed-content-card .card-title {
        color: var(--text-primary, #e0e0f0);
    }

    .feed-content-card .card-body {
        color: var(--text-secondary, #a0a0b0);
    }

    .feed-empty-state,
    .feed-error-state {
        color: var(--text-secondary, #a0a0b0);
    }

    .card-status-chips {
        border-top-color: var(--border-color, #2a2a3e);
    }

    .card-status-chips .status-chip {
        background: rgba(255, 255, 255, 0.05);
        color: var(--text-secondary, #a0a0b0);
        border-color: rgba(255, 255, 255, 0.1);
    }

    .card-status-chips .status-chip.status-unread {
        background: rgba(129, 140, 248, 0.15);
        color: #a5b4fc;
        border-color: rgba(129, 140, 248, 0.4);
    }

    .card-status-chips .status-chip.status-read {
        background: rgba(160, 160, 176, 0.1);
        color: #b0b0c0;
        border-color: rgba(160, 160, 176, 0.3);
    }

    .card-status-chips .status-chip.status-sent {
        background: rgba(251, 146, 60, 0.15);
        color: #fdba74;
        border-color: rgba(251, 146, 60, 0.4);
    }

    .card-status-chips .status-chip.status-received {
        background: rgba(16, 185, 129, 0.15);
        color: #6ee7b7;
        border-color: rgba(16, 185, 129, 0.4);
    }

    .card-status-chips .status-chip.status-unsent {
        background: rgba(239, 68, 68, 0.15);
        color: #fca5a5;
        border-color: rgba(239, 68, 68, 0.4);
    }

    .card-status-chips .status-timestamp {
        color: var(--text-secondary, #707080);
    }
}

/* ===== Print Styles ===== */

@media print {
    .feed-top-bar,
    .feed-filter-bar,
    .feed-privacy-bar,
    .feed-sentinel,
    .feed-loading {
        display: none !important;
    }

    .feed-content-card {
        page-break-inside: avoid;
    }
}