:root {
    --bg-primary: #f4f4f5;
    --bg-secondary: #f4f4f5;
    --surface: #ffffff;
    --surface-hover: #f0f0f4;
    --border: #e9e9ed;
    --text-primary: #4d4d4d;
    --text-secondary: #818c99;
    --text-meta: #6d7885;
    --accent: #2481cc;
    --accent-hover: #1b6ca8;
    --accent-light: #e8f0fe;
    --green: #50a95e;
    --red: #ed4a4a;
    --blue: #3a9cea;
    --orange: #f39c12;
    --purple: #8e44ad;
    --header-bg: rgba(255, 255, 255, 0.7);
    --header-shadow: 0 2px 4px rgba(0, 0, 0, 0.04);
    --media-radius: 0px;
    --card-radius: 16px;
    --font: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    --font-mono: 'SF Mono', 'Roboto Mono', monospace;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.02);
    --safe-top: env(safe-area-inset-top, 0px);
    --safe-bottom: env(safe-area-inset-bottom, 0px);
    --new-post-bg: rgba(51, 144, 236, 0.1);
    --edited-color: #8e9aa3;
    --delete-bg: rgba(237, 74, 74, 0.1);
    --status-dot-size: 10px;
    --transition-duration: 0.2s;
    --animation-duration: 0.3s;
}

:root[data-theme="dark"] {
    --bg-primary: #0e1621;
    --bg-secondary: #17212b;
    --surface: #17212b;
    --surface-hover: #202b36;
    --border: #2b3945;
    --text-primary: #cccccc;
    --text-secondary: #8e9aa3;
    --text-meta: #707d8b;
    --accent: #6ab3f3;
    --accent-hover: #5fa8e8;
    --accent-light: #253746;
    --header-bg: rgba(23, 33, 43, 0.7);
    --header-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
    --new-post-bg: rgba(106, 179, 243, 0.15);
    --edited-color: #707d8b;
    --delete-bg: rgba(237, 74, 74, 0.15);
}

@media (prefers-color-scheme: dark) {
    :root:not([data-theme="light"]) {
        --bg-primary: #0e1621;
        --bg-secondary: #17212b;
        --surface: #17212b;
        --surface-hover: #202b36;
        --border: #2b3945;
        --text-primary: #cccccc;
        --text-secondary: #8e9aa3;
        --text-meta: #707d8b;
        --accent: #6ab3f3;
        --accent-hover: #5fa8e8;
        --accent-light: #253746;
        --header-bg: rgba(23, 33, 43, 0.7);
        --header-shadow: 0 2px 4px rgba(0, 0, 0, 0.2);
        --new-post-bg: rgba(106, 179, 243, 0.15);
        --edited-color: #707d8b;
        --delete-bg: rgba(237, 74, 74, 0.15);
    }
}

/* Background Video */
.bg-video {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
    z-index: -1;
    opacity: 0;
    transition: opacity 2s ease-in-out;
    pointer-events: none;
    will-change: opacity;
}

.bg-video.visible {
    opacity: 0.1;
}

:root[data-theme="light"] .bg-video {
    opacity: 0;
    transition: none;
}

@media (max-width: 768px) {
    .bg-video.visible {
        opacity: 0.1;
    }
}

@media (prefers-reduced-motion: reduce) {
    .bg-video {
        transition: none;
    }
}

/* Reset */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-tap-highlight-color: transparent;
}

/* Media Loading States */
.media-loading {
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    color: var(--text-secondary);
    padding: 40px 20px;
    background: var(--bg-secondary);
    border-radius: var(--media-radius);
    border: 1px dashed var(--border);
}

.media-loader {
    width: 28px;
    height: 28px;
}

.media-error {
    text-align: center;
    color: var(--text-secondary);
    padding: 40px 20px;
    background: var(--bg-secondary);
    border-radius: var(--media-radius);
}

.media-unavailable {
    text-align: center;
    color: var(--text-secondary);
    padding: 20px;
    background: var(--bg-secondary);
    border-radius: var(--media-radius);
    font-style: italic;
    border: 1px solid var(--border);
}

.media-pending {
    text-align: center;
    color: var(--text-secondary);
    padding: 40px 20px;
    background: var(--bg-secondary);
    border-radius: var(--media-radius);
    border: 1px dashed var(--accent);
}

/* Body */
body {
    font-family: var(--font);
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.46668;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    transition: background-color var(--transition-duration) ease,
                color var(--transition-duration) ease;
}

/* Header */
.tg-header {
    position: sticky;
    top: 0;
    z-index: 90;
    backdrop-filter: blur(35px);
    -webkit-backdrop-filter: blur(35px);
    background: var(--header-bg);
    padding-top: var(--safe-top);
    transition: background-color var(--transition-duration) ease;
}

.channel-profile {
    max-width: 800px;
    margin: 0 auto;
    padding: 15px 20px;
    display: flex;
    align-items: center;
    gap: 16px;
}

.channel-avatar {
    width: 54px;
    height: 54px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    font-weight: 600;
    color: white;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    flex-shrink: 0;
    cursor: pointer;
    transition: transform var(--transition-duration) cubic-bezier(0.4, 0, 0.2, 1),
                box-shadow var(--transition-duration) ease;
    will-change: transform;
    overflow: hidden;
}

.channel-avatar:hover {
    transform: scale(1.05);
    box-shadow: 0 6px 12px rgba(0, 0, 0, 0.15);
}

.channel-avatar:active {
    transform: scale(0.95);
}

.channel-avatar:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

.channel-info {
    flex: 1;
    min-width: 0;
}

.channel-title-row {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-bottom: 2px;
}

.channel-title {
    font-size: 20px;
    font-weight: 700;
    letter-spacing: -0.3px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
    transition: color var(--transition-duration) ease;
}

.status-dot {
    width: var(--status-dot-size);
    height: var(--status-dot-size);
    border-radius: 50%;
    background: var(--green);
    animation: pulse 2s infinite;
    transition: background-color var(--transition-duration) ease;
}

.status-dot.offline {
    background: var(--red);
    animation: none;
}

@keyframes pulse {
    0% { transform: scale(1); opacity: 1; }
    50% { transform: scale(1.2); opacity: 0.7; }
    100% { transform: scale(1); opacity: 1; }
}

.channel-meta {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--text-secondary);
    font-size: 14px;
    transition: color var(--transition-duration) ease;
}

.channel-badge {
    background: var(--accent-light);
    color: var(--accent);
    padding: 2px 10px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 500;
    transition: all var(--transition-duration) ease;
}

/* New Posts Badge */
.new-posts-badge {
    background: var(--accent);
    color: white;
    border-radius: 20px;
    padding: 12px 12px;
    font-size: 12px;
    font-weight: 600;
    cursor: pointer;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
    transition: all var(--transition-duration) cubic-bezier(0.4, 0, 0.2, 1);
    white-space: nowrap;
    display: flex;
    align-items: center;
    gap: 8px;
    will-change: transform, opacity;
}

.new-posts-badge.hidden {
    display: none;
}

.new-posts-badge:hover {
    background: var(--accent-hover);
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

.new-posts-badge:active {
    transform: translateY(0);
}

.new-posts-badge:focus-visible {
    outline: 2px solid white;
    outline-offset: 2px;
}

.new-dot {
    width: 8px;
    height: 8px;
    background: #ffeb3b;
    border-radius: 50%;
    animation: pulse 1.5s infinite;
}

/* Feed */
.feed {
    max-width: 800px;
    margin: 0 auto;
    padding: 8px 10px 20px;
    display: flex;
    flex-direction: column;
    gap: 12px;
    contain: layout style paint;
}

/* Posts */
.post {
    background: var(--surface);
    border-radius: var(--card-radius);
    overflow: hidden;
    transition: transform 0.4s cubic-bezier(0.23, 1, 0.32, 1),
                opacity 0.4s cubic-bezier(0.23, 1, 0.32, 1),
                background-color 0.4s ease;
    opacity: 0;
    transform: translateY(20px);
    will-change: transform, opacity, background-color;
}

.post.visible {
    opacity: 1;
    transform: translateY(0);
}

.post.new {
    animation: newPostHighlight 3000ms ease-out forwards;
}

@keyframes newPostHighlight {
    0% { background: var(--new-post-bg); }
    100% { background: var(--surface); }
}

.post.updated {
    background: var(--accent-light);
}

.post.deleted {
    opacity: 0;
    transform: translateX(-20px);
    pointer-events: none;
    transition: opacity var(--animation-duration) ease,
                transform var(--animation-duration) ease;
}

.post-content {
    padding: 20px 20px 10px;
}

.post-header {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 10px;
}

.post-avatar {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: 600;
    font-size: 15px;
    flex-shrink: 0;
    overflow: hidden;
}

.post-author-info {
    flex: 1;
    min-width: 0;
}

.post-author-name {
    font-weight: 650;
    font-size: 15px;
    color: var(--text-primary);
    margin-bottom: 0px;
    display: flex;
    align-items: baseline;
    gap: 6px;
    flex-wrap: wrap;
    transition: color var(--transition-duration) ease;
}

.post-username {
    font-size: 11px;
    color: var(--text-secondary);
}

.post-date {
    color: var(--text-secondary);
    font-size: 12px;
    display: flex;
    align-items: baseline;
    gap: 4px;
    flex-wrap: wrap;
    transition: color var(--transition-duration) ease;
}

.edited-mark {
    font-size: 10px;
    color: var(--edited-color);
}

.post-text {
    font-size: 14px;
    line-height: 1.4;
    margin-bottom: 10px;
    white-space: normal;
    word-wrap: break-word;
    color: var(--text-primary);
    transition: color var(--transition-duration) ease;
}

.post-text a {
    color: var(--accent);
    text-decoration: none;
}

.post-text a:hover {
    text-decoration: underline;
}

/* Media Container */
.media-container {
    border-radius: var(--media-radius);
    overflow: hidden;
    margin-bottom: 5px;
    background: var(--bg-secondary);
    position: relative;
    cursor: pointer;
    min-height: 200px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: background-color var(--transition-duration) ease;
}

.media-container img,
.media-container video {
    width: 100%;
    max-height: 500px;
    object-fit: contain;
    display: block;
    background: transparent;
}

.media-container video {
    background: #000;
}

.media-container video:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

/* Post Footer */
.post-footer {
    display: flex;
    align-items: center;
    padding: 8px 15px 8px;
    border-top: 1px solid var(--border);
    color: var(--text-secondary);
    font-size: 14px;
    transition: all var(--transition-duration) ease;
}

.views-count {
    display: flex;
    align-items: center;
    gap: 4px;
}

/* Code Blocks */
.tg-code-block {
    background: var(--bg-secondary);
    padding: 16px;
    border-radius: 12px;
    overflow-x: auto;
    font-family: var(--font-mono);
    font-size: 13px;
    line-height: 1.45;
    margin: 12px 0;
    border: 1px solid var(--border);
    position: relative;
    transition: all var(--transition-duration) ease;
}

.tg-code-block::before {
    content: '```';
    position: absolute;
    top: 8px;
    right: 12px;
    color: var(--text-meta);
    font-size: 12px;
    opacity: 0.5;
    transition: color var(--transition-duration) ease;
}

.tg-inline-code {
    padding: 5px 0px;
    font-family: var(--font-mono);
    font-size: 0.9em;
    color: var(--accent);
    transition: all var(--transition-duration) ease;
}

/* Quotes */
.tg-quote {
    border-left: 3px solid var(--accent);
    padding: 8px 0 8px 12px;
    margin: 8px 0;
    color: var(--text-secondary);
    background: var(--bg-secondary);
    border-radius: 0 8px 8px 0;
    transition: all var(--transition-duration) ease;
}

.tg-quote.level-2 {
    border-left-color: var(--green);
}

.tg-quote.level-3 {
    border-left-color: var(--orange);
}

@media (max-width: 600px) {
    .tg-quote.level-2,
    .tg-quote.level-3 {
        margin-left: 8px;
    }
}

/* Spoiler */
.tg-spoiler {
    background: var(--text-secondary);
    color: transparent;
    cursor: pointer;
    transition: all var(--transition-duration) ease;
    border-radius: 4px;
    padding: 0 2px;
}

.tg-spoiler.revealed {
    background: transparent;
    color: inherit;
    animation: spoilerReveal var(--animation-duration) ease;
}

@keyframes spoilerReveal {
    0% {
        filter: blur(4px);
        opacity: 0.5;
    }
    100% {
        filter: blur(0);
        opacity: 1;
    }
}

/* Mentions & Hashtags */
.tg-mention {
    color: var(--accent);
    cursor: pointer;
    font-weight: 500;
    transition: all var(--transition-duration) ease;
}

.tg-mention:hover {
    text-decoration: underline;
    background: var(--accent-light);
    border-radius: 4px;
}

.tg-mention:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

.tg-hashtag {
    color: var(--accent);
    cursor: pointer;
    font-weight: 500;
    transition: all var(--transition-duration) ease;
}

.tg-hashtag:hover {
    text-decoration: underline;
    background: var(--accent-light);
    border-radius: 4px;
}

.tg-hashtag:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

/* Links */
.tg-link {
    word-break: break-word;
    display: inline;
    color: var(--accent);
    text-decoration: none;
    border-bottom: 1px dashed var(--accent-light);
    transition: all var(--transition-duration) ease;
    white-space: normal;
}

.tg-link:hover {
    border-bottom-style: solid;
}

.tg-link:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

.tg-link::after {
    content: attr(data-domain);
    font-size: 10px;
    color: var(--text-meta);
    margin-left: 4px;
    text-transform: lowercase;
    transition: color var(--transition-duration) ease;
}

.heartSVG {
    width: 24px;
    height: 24px;
    flex-shrink: 0;
}

.heart-btn {
    background: none;
    border: none;
    cursor: pointer;
    padding: 0;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 13px;
    color: var(--text-secondary);
}


/* Lightbox */
.lightbox {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.95);
    z-index: 1000;
    display: none;
    align-items: center;
    justify-content: center;
    backdrop-filter: blur(10px);
    transition: opacity var(--animation-duration) ease;
}

.lightbox.active {
    display: flex;
    animation: lightboxFadeIn var(--animation-duration) ease;
}

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

.lightbox-content {
    max-width: 90vw;
    max-height: 90vh;
    position: relative;
    animation: lightboxScaleIn var(--animation-duration) cubic-bezier(0.4, 0, 0.2, 1);
}

@keyframes lightboxScaleIn {
    from {
        transform: scale(0.9);
        opacity: 0;
    }
    to {
        transform: scale(1);
        opacity: 1;
    }
}

.lightbox-content img,
.lightbox-content video {
    max-width: 100%;
    max-height: 90vh;
    object-fit: contain;
    border-radius: 8px;
}

.lightbox-close {
    position: absolute;
    top: 20px;
    right: 20px;
    width: 44px;
    height: 44px;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    border: none;
    border-radius: 50%;
    color: white;
    font-size: 24px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1001;
    transition: all var(--transition-duration) ease;
    will-change: transform, background-color;
}

.lightbox-close:hover {
    background: rgba(0, 0, 0, 0.7);
    transform: scale(1.1);
}

.lightbox-close:active {
    transform: scale(0.9);
}

.lightbox-close:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

/* Scroll Top Button */
.scroll-top {
    position: fixed;
    bottom: 20px;
    right: 20px;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: var(--surface-hover);
    color: var(--text-primary);
    border: none;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
    font-size: 24px;
    cursor: pointer;
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 89;
    transition: all var(--transition-duration) cubic-bezier(0.4, 0, 0.2, 1);
    will-change: transform, opacity, background-color;
}

.scroll-top:hover {
    transform: scale(1.1);
    background: var(--border);
}

.scroll-top:active {
    transform: scale(0.9);
}

.scroll-top:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

/* Infinite Scroll */
.infinite-scroll-trigger {
    height: 20px;
    margin: 10px 0 20px;
    text-align: center;
    color: var(--text-secondary);
    font-size: 13px;
    transition: color var(--transition-duration) ease;
}

/* Skeleton Loading */
.skeleton {
    background: linear-gradient(90deg,
        var(--surface) 25%,
        var(--surface-hover) 50%,
        var(--surface) 75%);
    background-size: 200% 100%;
    animation: loading 1.5s infinite;
    border-radius: var(--card-radius);
    height: 200px;
    margin-bottom: 12px;
}

@keyframes loading {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

/* Toast Notifications */
.toast {
    position: fixed;
    bottom: 20px;
    left: 50%;
    transform: translateX(-50%);
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: 30px;
    padding: 10px 20px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    z-index: 1000;
    display: flex;
    align-items: center;
    gap: 8px;
    animation: slideUp 0.3s ease;
    max-width: 90%;
    word-break: break-word;
    transition: all var(--transition-duration) ease;
}

.toast.info { border-left: 4px solid var(--accent); }
.toast.success { border-left: 4px solid var(--green); }
.toast.warning { border-left: 4px solid var(--orange); }
.toast.error { border-left: 4px solid var(--red); }

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translate(-50%, 20px);
    }
    to {
        opacity: 1;
        transform: translate(-50%, 0);
    }
}

/* Theme Transition */
.theme-transitioning * {
    transition: background-color 0.35s ease,
                color 0.35s ease,
                border-color 0.35s ease !important;
}

/* Responsive */
@media (max-width: 600px) {
    .channel-profile {
        padding: 12px 16px;
    }
    .channel-title {
        font-size: 18px;
    }
    .post-content {
        padding: 14px 14px 5px;
    }
    .new-posts-badge {
        padding: 12px 12px;
        font-size: 12px;
    }
    .toast {
        max-width: 95%;
        font-size: 14px;
    }
    :root {
        --status-dot-size: 8px;
        --transition-duration: 0.15s;
    }
}

/* Reduced Motion */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
}