/* ============================================================
   MP4WEB — SEO优化重设计版
   参考 FreeConvert 布局风格：专业克制、内容丰富、结构清晰
   ============================================================ */

:root {
    --primary: #727CF5;
    --primary-hover: #656EE0;
    --primary-light: #EEF0FE;
    --primary-dark: #5A63D0;
    --failure: #F45F6D;
    --success: #2EBF6E;
    --info: #368FFF;
    --warning: #F9C750;
    --purple: #8B5CF6;

    --black: #212121;
    --text: #2D3748;
    --text-secondary: #7987A1;
    --white: #FFFFFF;

    --bg: #F5F4F3;
    --surface: #FFFFFF;
    --border: #E3E5E8;
    --border-light: #F0F1F4;
    --footer-bg: #1E2431;
    --footer-text: rgba(255,255,255,0.55);

    --radius-sm: 4px;
    --radius: 8px;
    --radius-md: 12px;
    --radius-card: 14px;
    --radius-pill: 999px;

    --shadow-xs: 0 1px 2px rgba(33,33,33,0.05);
    --shadow-sm: 0 2px 8px rgba(33,33,33,0.06);
    --shadow: 0 4px 20px rgba(33,33,33,0.08);
    --shadow-lg: 0 12px 40px rgba(114,124,245,0.14);
    --shadow-xl: 0 24px 60px rgba(33,33,33,0.12);

    --container: 1200px;
    --container-narrow: 860px;
}

/* ============ Reset ============ */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    background-color: var(--bg);
    color: var(--text);
    min-height: 100vh;
    overflow-x: hidden;
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* ============ Layout Utilities ============ */
.container {
    max-width: var(--container);
    margin: 0 auto;
    padding: 0 1.5rem;
}

.text-center { text-align: center; }
.hidden { display: none !important; }

.glass-effect {
    background: var(--surface);
    border: 1px solid var(--border);
    box-shadow: var(--shadow);
}

.gradient-text {
    background: linear-gradient(135deg, var(--primary) 0%, var(--purple) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

/* ============ Navbar ============ */
.navbar {
    position: sticky;
    top: 0;
    width: 100%;
    z-index: 100;
    background: var(--surface);
    border-bottom: 1px solid var(--border);
}

.nav-content {
    max-width: var(--container);
    margin: 0 auto;
    padding: 0 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 60px;
    gap: 1rem;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.2rem;
    font-weight: 800;
    color: var(--black);
    text-decoration: none;
    letter-spacing: -0.02em;
    flex-shrink: 0;
}

.logo svg { flex-shrink: 0; }

.nav-links {
    display: flex;
    gap: 0.25rem;
    flex: 1;
    justify-content: center;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.9rem;
    padding: 0.4rem 0.85rem;
    border-radius: var(--radius-pill);
    transition: color 0.2s, background 0.2s;
}

.nav-links a:hover {
    color: var(--primary);
    background: var(--primary-light);
}

.nav-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.4rem;
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--success);
    background: rgba(46, 191, 110, 0.1);
    padding: 0.3rem 0.75rem;
    border-radius: var(--radius-pill);
    border: 1px solid rgba(46, 191, 110, 0.2);
    white-space: nowrap;
    flex-shrink: 0;
}

/* ============ Buttons ============ */
button, .btn-primary, .btn-primary-outline, .btn-secondary {
    cursor: pointer;
    font-family: inherit;
    border: none;
    outline: none;
    border-radius: var(--radius-pill);
    transition: all 0.2s ease;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    text-decoration: none;
    font-weight: 600;
    white-space: nowrap;
}

.btn-primary {
    background: var(--primary);
    color: var(--white);
    padding: 0.75rem 1.75rem;
    font-size: 0.95rem;
}

.btn-primary:hover {
    background: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: 0 4px 14px rgba(114,124,245,0.35);
}

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

.btn-secondary {
    background: var(--surface);
    color: var(--text);
    padding: 0.75rem 1.5rem;
    font-size: 0.95rem;
    border: 1px solid var(--border);
}

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

.btn-primary.large { padding: 0.9rem 2.25rem; font-size: 1rem; }

.btn-section-cta {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: var(--primary);
    color: var(--white);
    padding: 0.8rem 1.75rem;
    border-radius: var(--radius-pill);
    font-size: 0.95rem;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.2s;
    margin-top: 1.5rem;
}

.btn-section-cta:hover {
    background: var(--primary-hover);
    transform: translateY(-1px);
    box-shadow: 0 4px 14px rgba(114,124,245,0.35);
}

/* ============ Hero Section ============ */
.hero-section {
    padding: 4.5rem 1.5rem 3.5rem;
    background: var(--bg);
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
}

.hero-content {
    max-width: 760px;
    width: 100%;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.4rem 1rem;
    border-radius: var(--radius-pill);
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--primary);
    background: var(--primary-light);
    border: 1px solid rgba(114,124,245,0.2);
    margin-bottom: 1.5rem;
    letter-spacing: 0.01em;
}

.pulse {
    width: 8px;
    height: 8px;
    background-color: var(--success);
    border-radius: 50%;
    animation: pulse 2s infinite;
    flex-shrink: 0;
}

@keyframes pulse {
    0% { box-shadow: 0 0 0 0 rgba(46,191,110,0.5); }
    70% { box-shadow: 0 0 0 8px rgba(46,191,110,0); }
    100% { box-shadow: 0 0 0 0 rgba(46,191,110,0); }
}

h1 {
    font-size: 2.9rem;
    font-weight: 900;
    line-height: 1.12;
    margin-bottom: 1.25rem;
    letter-spacing: -0.03em;
    color: var(--black);
}

.subtitle {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 2.25rem;
    max-width: 580px;
    line-height: 1.7;
}

.subtitle strong {
    color: var(--text);
    font-weight: 600;
}

/* ============ Search Container ============ */
.search-container {
    display: flex;
    align-items: center;
    width: 100%;
    padding: 0.45rem 0.45rem 0.45rem 1.25rem;
    border-radius: var(--radius-card);
    margin-bottom: 1rem;
    background: var(--surface);
    border: 2px solid var(--border);
    transition: border-color 0.2s, box-shadow 0.2s;
}

.search-container:focus-within {
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(114,124,245,0.1);
}

.search-icon {
    color: var(--text-secondary);
    flex-shrink: 0;
    margin-right: 0.5rem;
}

.search-container input {
    flex: 1;
    background: transparent;
    border: none;
    outline: none;
    color: var(--text);
    font-size: 1rem;
    font-family: inherit;
    padding: 0.9rem 0;
    min-width: 0;
}

.search-container input::placeholder { color: var(--text-secondary); }

.search-container .btn-primary {
    padding: 0.85rem 1.75rem;
    flex-shrink: 0;
    border-radius: 10px;
}

/* URL Tips */
.url-tips {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex-wrap: wrap;
    justify-content: center;
    margin-bottom: 2.5rem;
}

.tip-label {
    font-size: 0.82rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.tip-chip {
    font-size: 0.78rem;
    font-weight: 500;
    color: var(--text-secondary);
    background: var(--surface);
    border: 1px solid var(--border);
    padding: 0.2rem 0.6rem;
    border-radius: var(--radius-pill);
    cursor: default;
    transition: all 0.15s;
}

.tip-chip:hover {
    color: var(--primary);
    border-color: var(--primary);
    background: var(--primary-light);
}

/* Status Messages */
.status-message, .error-message {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    margin-top: 0.75rem;
    font-size: 0.95rem;
    font-weight: 500;
}

.status-message { color: var(--primary); }
.error-message { color: var(--failure); }

.spinner {
    width: 18px;
    height: 18px;
    border: 2px solid rgba(114,124,245,0.25);
    border-radius: 50%;
    border-top-color: var(--primary);
    animation: spin 0.8s linear infinite;
    flex-shrink: 0;
}

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

/* Result Card */
.result-card {
    width: 100%;
    margin-top: 1.5rem;
    border-radius: var(--radius-card);
    padding: 1.75rem;
    text-align: left;
}

.result-layout {
    display: flex;
    gap: 1.5rem;
    align-items: center;
}

.thumbnail-wrapper {
    position: relative;
    width: 200px;
    height: 112px;
    border-radius: var(--radius);
    overflow: hidden;
    flex-shrink: 0;
    background: var(--bg);
}

.thumbnail-wrapper img { width: 100%; height: 100%; object-fit: cover; }

.play-overlay {
    position: absolute;
    top: 50%; left: 50%;
    transform: translate(-50%, -50%);
    width: 42px; height: 42px;
    background: var(--primary);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0.95;
    pointer-events: none;
}

.result-details { flex: 1; min-width: 0; }

.video-title {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 0.4rem;
    color: var(--black);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.video-meta {
    display: flex;
    align-items: center;
    gap: 0.3rem;
    color: var(--success);
    font-weight: 500;
    margin-bottom: 1.25rem;
    font-size: 0.9rem;
}

.action-buttons { display: flex; gap: 0.75rem; flex-wrap: wrap; }

/* Trust Bar */
.trust-bar {
    display: flex;
    align-items: center;
    gap: 2rem;
    padding: 1.25rem 2.5rem;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-card);
    margin-top: 2rem;
}

.trust-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.15rem;
}

.trust-item strong {
    font-size: 1.6rem;
    font-weight: 800;
    color: var(--primary);
    line-height: 1;
    letter-spacing: -0.02em;
}

.trust-item span {
    font-size: 0.78rem;
    color: var(--text-secondary);
    font-weight: 500;
}

.trust-divider {
    width: 1px;
    height: 36px;
    background: var(--border);
    flex-shrink: 0;
}

/* ============ Section Shared ============ */
.section-header {
    text-align: center;
    margin-bottom: 3rem;
}

.section-tag {
    display: inline-block;
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--primary);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: 0.75rem;
    background: var(--primary-light);
    padding: 0.3rem 0.85rem;
    border-radius: var(--radius-pill);
}

.section-header h2 {
    font-size: 2.1rem;
    font-weight: 800;
    color: var(--black);
    letter-spacing: -0.025em;
    margin-bottom: 0.75rem;
    line-height: 1.2;
}

.section-subtitle {
    font-size: 1.05rem;
    color: var(--text-secondary);
    max-width: 580px;
    margin: 0 auto;
    line-height: 1.7;
}

/* ============ How To Use ============ */
.section-how-to {
    padding: 5rem 1.5rem;
    background: var(--surface);
}

.steps-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    position: relative;
}

.steps-grid::before {
    content: '';
    position: absolute;
    top: 36px;
    left: calc(33.33% - 0px);
    right: calc(33.33% - 0px);
    height: 2px;
    background: linear-gradient(90deg, var(--primary-light), var(--primary), var(--primary-light));
    z-index: 0;
}

.step-card {
    background: var(--bg);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-card);
    padding: 2rem 1.75rem;
    text-align: center;
    position: relative;
    transition: transform 0.2s, box-shadow 0.2s;
}

.step-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow);
}

.step-icon {
    width: 72px;
    height: 72px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.25rem;
    position: relative;
}

.step-icon--blue { background: rgba(114,124,245,0.1); }
.step-icon--purple { background: rgba(139,92,246,0.1); }
.step-icon--green { background: rgba(46,191,110,0.1); }

.step-number {
    position: absolute;
    top: -4px;
    right: -4px;
    width: 22px;
    height: 22px;
    background: var(--primary);
    color: white;
    border-radius: 50%;
    font-size: 0.75rem;
    font-weight: 700;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 2px solid var(--surface);
}

.step-card h3 {
    font-size: 1.1rem;
    font-weight: 700;
    color: var(--black);
    margin-bottom: 0.75rem;
}

.step-card p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.65;
}

/* ============ Platforms Section ============ */
.section-platforms {
    padding: 5rem 1.5rem;
    background: var(--bg);
}

.platforms-featured {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
    margin-bottom: 2.5rem;
}

.platform-card--featured {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-card);
    padding: 1.5rem;
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    position: relative;
    transition: all 0.2s;
}

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

.platform-logo {
    flex-shrink: 0;
    width: 48px;
    height: 48px;
    border-radius: 12px;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s ease;
}

.platform-logo img.real-logo {
    width: 24px;
    height: 24px;
    object-fit: contain;
    transition: all 0.3s ease;
}

/* 品牌特有背景色与滤镜 */
.logo-youtube {
    background-color: #ff0000;
}
.logo-youtube img.real-logo {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.logo-tiktok {
    background-color: #000000;
}
.logo-tiktok img.real-logo {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.logo-bilibili {
    background-color: #fb7299;
}
.logo-bilibili img.real-logo {
    filter: brightness(0) invert(1);
}

.logo-x {
    background-color: #0F1419;
}
.logo-x img.real-logo {
    filter: brightness(0) invert(1);
}

.logo-instagram {
    background: linear-gradient(45deg, #f09433 0%, #e6683c 25%, #dc2743 50%, #cc2366 75%, #bc1888 100%);
}
.logo-instagram img.real-logo {
    filter: brightness(0) invert(1);
}

.logo-kuaishou {
    background-color: #ff6900;
}
.logo-kuaishou img.real-logo {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

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

.platform-info h3 {
    font-size: 1rem;
    font-weight: 700;
    color: var(--black);
    margin-bottom: 0.3rem;
}

.platform-info p {
    font-size: 0.82rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

.platform-badge {
    position: absolute;
    top: 0.75rem;
    right: 0.75rem;
    font-size: 0.7rem;
    font-weight: 700;
    padding: 0.15rem 0.5rem;
    border-radius: var(--radius-pill);
    background: var(--primary-light);
    color: var(--primary);
    border: 1px solid rgba(114,124,245,0.2);
}

.platform-badge--hot {
    background: rgba(254, 44, 85, 0.08);
    color: #FE2C55;
    border-color: rgba(254,44,85,0.2);
}

.platforms-all {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-card);
    padding: 1.75rem;
}

.platforms-all-title {
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 1rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.platform-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.platform-tag {
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
    font-size: 0.82rem;
    font-weight: 500;
    color: var(--text);
    background: var(--bg);
    border: 1px solid var(--border);
    padding: 0.3rem 0.75rem;
    border-radius: var(--radius-pill);
    cursor: default;
    transition: all 0.15s;
}

.platform-tag .tag-logo {
    width: 14px;
    height: 14px;
    object-fit: contain;
    display: inline-block;
    flex-shrink: 0;
    transition: filter 0.15s ease;
}

.platform-tag:hover {
    background: var(--primary-light);
    border-color: var(--primary);
    color: var(--primary);
}

/* 在 hover 时或者在深色背景下让小 logo 变白以保证清晰可见 */
.platform-tag:hover .tag-logo {
    filter: brightness(0) invert(1);
}

/* 标签更多按钮样式 */
.platform-tag-more {
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--primary);
    background: var(--primary-light);
    border: 1px solid rgba(114, 124, 245, 0.25);
    padding: 0.3rem 0.75rem;
    border-radius: var(--radius-pill);
    cursor: pointer;
    transition: all 0.15s;
}

.platform-tag-more:hover {
    background: var(--primary);
    color: white;
}

/* ============ Features Section ============ */
.section-features {
    padding: 5rem 1.5rem;
    background: var(--surface);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.25rem;
}

.feature-card {
    background: var(--bg);
    border: 1px solid var(--border-light);
    border-radius: var(--radius-card);
    padding: 1.75rem;
    transition: all 0.2s;
}

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

.feature-icon {
    width: 48px;
    height: 48px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.25rem;
}

.feature-card h3 {
    font-size: 1.05rem;
    font-weight: 700;
    color: var(--black);
    margin-bottom: 0.6rem;
}

.feature-card p {
    font-size: 0.88rem;
    color: var(--text-secondary);
    line-height: 1.65;
}

/* ============ Content Sections (SEO) ============ */
.section-content {
    padding: 5rem 1.5rem;
    background: var(--bg);
}

.section-content--alt {
    background: var(--surface);
}

.content-layout {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
    align-items: center;
    max-width: var(--container-narrow);
    margin: 0 auto;
}

.content-layout--reverse .content-text { order: 2; }
.content-layout--reverse .content-visual { order: 1; }

.content-text .section-tag { display: inline-block; margin-bottom: 0.75rem; }

.content-text h2 {
    font-size: 1.9rem;
    font-weight: 800;
    color: var(--black);
    letter-spacing: -0.025em;
    line-height: 1.25;
    margin-bottom: 1rem;
}

.content-text p {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.75;
    margin-bottom: 0.75rem;
}

.content-text p strong {
    color: var(--text);
    font-weight: 600;
}

.content-text code {
    font-family: 'SF Mono', 'Monaco', 'Courier New', monospace;
    font-size: 0.85rem;
    background: var(--primary-light);
    color: var(--primary);
    padding: 0.1em 0.4em;
    border-radius: 4px;
}

.content-list {
    list-style: none;
    margin: 1.25rem 0;
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
}

.content-list li {
    display: flex;
    align-items: center;
    gap: 0.6rem;
    font-size: 0.9rem;
    color: var(--text);
    font-weight: 500;
}

/* Visual Cards */
.content-visual { position: relative; }

.visual-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-card);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

.visual-card--dark {
    background: #1a1d2e;
    border-color: #2d3050;
}

.visual-card-header {
    display: flex;
    align-items: center;
    gap: 0.4rem;
    padding: 0.85rem 1.25rem;
    border-bottom: 1px solid #2d3050;
    background: #131625;
}

.vc-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
}
.vc-dot--red { background: #FF5F57; }
.vc-dot--yellow { background: #FEBC2E; }
.vc-dot--green { background: #28C840; }

.vc-title {
    margin-left: auto;
    font-size: 0.75rem;
    color: rgba(255,255,255,0.4);
    font-weight: 500;
}

.vc-body { padding: 1.25rem; }

.vc-url-bar {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    background: rgba(255,255,255,0.05);
    border: 1px solid rgba(255,255,255,0.08);
    border-radius: 6px;
    padding: 0.5rem 0.75rem;
    margin-bottom: 1rem;
}

.vc-url-bar span {
    font-size: 0.72rem;
    color: rgba(255,255,255,0.45);
    font-family: monospace;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.vc-video-preview {
    display: flex;
    gap: 0.875rem;
    align-items: center;
}

.vc-thumb {
    width: 80px;
    height: 55px;
    background: rgba(255,0,0,0.08);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    flex-shrink: 0;
    border: 1px solid rgba(255,255,255,0.08);
}

.vc-quality-badge {
    position: absolute;
    bottom: 3px;
    right: 3px;
    background: var(--primary);
    color: white;
    font-size: 0.58rem;
    font-weight: 700;
    padding: 1px 4px;
    border-radius: 3px;
}

.vc-meta { flex: 1; }

.vc-title-line {
    height: 10px;
    background: rgba(255,255,255,0.12);
    border-radius: 4px;
    margin-bottom: 6px;
    width: 90%;
}

.vc-sub-line {
    height: 8px;
    background: rgba(255,255,255,0.07);
    border-radius: 4px;
    width: 60%;
    margin-bottom: 10px;
}

.vc-actions { display: flex; gap: 6px; }

.vc-btn {
    font-size: 0.68rem;
    font-weight: 600;
    padding: 0.3rem 0.65rem;
    border-radius: 20px;
}

.vc-btn--primary { background: var(--primary); color: white; }
.vc-btn--secondary { background: rgba(255,255,255,0.1); color: rgba(255,255,255,0.7); border: 1px solid rgba(255,255,255,0.1); }

/* Platform List in visual */
.vc-platform-list { padding: 1.25rem; display: flex; flex-direction: column; gap: 0.875rem; }

.vc-platform-item {
    display: flex;
    align-items: center;
    gap: 0.875rem;
    padding: 0.75rem;
    background: var(--bg);
    border: 1px solid var(--border-light);
    border-radius: 10px;
    transition: all 0.15s;
}

.vc-platform-item:hover {
    border-color: var(--border);
    background: var(--surface);
}

.vc-p-icon {
    width: 36px;
    height: 36px;
    border-radius: 9px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.vc-p-name {
    font-size: 0.88rem;
    font-weight: 600;
    color: var(--black);
    margin-bottom: 0.15rem;
}

.vc-p-status {
    font-size: 0.75rem;
    font-weight: 500;
}

.vc-p-status--ok { color: var(--success); }

/* ============ FAQ Section ============ */
.section-faq {
    padding: 5rem 1.5rem;
    background: var(--bg);
}

.faq-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    max-width: 1000px;
    margin: 0 auto;
}

.faq-item {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-card);
    overflow: hidden;
    transition: border-color 0.2s;
}

.faq-item[open] {
    border-color: var(--primary);
}

.faq-question {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1.25rem 1.5rem;
    cursor: pointer;
    list-style: none;
    gap: 1rem;
    user-select: none;
}

.faq-question::-webkit-details-marker { display: none; }

.faq-q-content {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    flex: 1;
}

.faq-icon {
    width: 36px;
    height: 36px;
    background: var(--primary-light);
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.faq-q-content span {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--black);
}

.faq-chevron {
    color: var(--text-secondary);
    flex-shrink: 0;
    transition: transform 0.2s;
}

.faq-item[open] .faq-chevron { transform: rotate(180deg); }

.faq-answer {
    padding: 0 1.5rem 1.25rem;
    border-top: 1px solid var(--border-light);
    margin-top: -1px;
}

.faq-answer p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.75;
    margin-top: 1rem;
}

.faq-answer strong {
    color: var(--text);
    font-weight: 600;
}

/* ============ CTA Banner ============ */
.section-cta {
    padding: 4rem 1.5rem;
    background: var(--surface);
}

.cta-banner {
    background: linear-gradient(135deg, var(--primary) 0%, var(--purple) 100%);
    border-radius: 20px;
    padding: 4rem 3rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 2rem;
    position: relative;
    overflow: hidden;
}

.cta-content { position: relative; z-index: 1; }

.cta-content h2 {
    font-size: 2rem;
    font-weight: 800;
    color: white;
    margin-bottom: 0.75rem;
    letter-spacing: -0.025em;
}

.cta-content p {
    font-size: 1rem;
    color: rgba(255,255,255,0.8);
    margin-bottom: 1.75rem;
}

.btn-cta {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: white;
    color: var(--primary);
    padding: 0.9rem 2rem;
    border-radius: var(--radius-pill);
    font-size: 1rem;
    font-weight: 700;
    text-decoration: none;
    transition: all 0.2s;
    border: none;
    cursor: pointer;
}

.btn-cta:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(0,0,0,0.2);
}

.cta-decoration {
    position: absolute;
    right: -30px;
    top: -40px;
    pointer-events: none;
}

.cta-circles { position: relative; width: 280px; height: 280px; }

.cta-circle {
    position: absolute;
    border-radius: 50%;
    border: 1px solid rgba(255,255,255,0.15);
}

.cta-circle--1 { width: 200px; height: 200px; top: 20px; right: 20px; }
.cta-circle--2 { width: 140px; height: 140px; top: 50px; right: 50px; }
.cta-circle--3 { width: 80px; height: 80px; top: 80px; right: 80px; background: rgba(255,255,255,0.08); }

/* ============ Footer ============ */
.footer {
    background: var(--footer-bg);
    padding: 4rem 1.5rem 2rem;
}

.footer-top {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 3rem;
    margin-bottom: 3rem;
    padding-bottom: 3rem;
    border-bottom: 1px solid rgba(255,255,255,0.08);
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 1.15rem;
    font-weight: 800;
    color: white;
    text-decoration: none;
    margin-bottom: 1rem;
}

.footer-tagline {
    font-size: 0.88rem;
    color: var(--footer-text);
    line-height: 1.65;
    max-width: 280px;
}

.footer-links-groups {
    display: flex;
    gap: 4rem;
}

.footer-links-group h4 {
    font-size: 0.8rem;
    font-weight: 700;
    color: rgba(255,255,255,0.5);
    text-transform: uppercase;
    letter-spacing: 0.08em;
    margin-bottom: 1rem;
}

.footer-links-group ul {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
}

.footer-links-group a {
    font-size: 0.88rem;
    color: var(--footer-text);
    text-decoration: none;
    transition: color 0.15s;
}

.footer-links-group a:hover { color: var(--primary); }

.footer-bottom {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    text-align: center;
}
.footer-bottom p {
    font-size: 0.8rem;
    color: rgba(255,255,255,0.3);
    text-align: center;
    margin: 0;
}
.footer-bottom-links {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.75rem 1.5rem;
}
.footer-bottom-links a {
    font-size: 0.8rem;
    color: rgba(255,255,255,0.3);
    text-decoration: none;
    transition: color 0.15s;
}
.footer-bottom-links a:hover { color: var(--primary); }

.footer-disclaimer {
    margin-top: 0.4rem;
    font-size: 0.75rem !important;
    color: rgba(255,255,255,0.2) !important;
}

/* ============ Animations ============ */
.fade-in-up {
    opacity: 0;
    transform: translateY(16px);
    animation: fadeInUp 0.65s forwards cubic-bezier(0.22, 1, 0.36, 1);
}

.delay-1 { animation-delay: 0.1s; }
.delay-2 { animation-delay: 0.2s; }
.delay-3 { animation-delay: 0.3s; }

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

/* ============ Responsive ============ */
@media (max-width: 1024px) {
    .platforms-featured { grid-template-columns: repeat(2, 1fr); }
    .features-grid { grid-template-columns: repeat(2, 1fr); }
    .content-layout { gap: 2.5rem; }
    .footer-top { grid-template-columns: 1fr; gap: 2rem; }
    .footer-links-groups { gap: 2rem; }
}

@media (max-width: 768px) {
    h1 { font-size: 2.1rem; }
    .hero-section { padding: 3rem 1.25rem; }
    .subtitle { font-size: 1rem; }

    .nav-links { display: none; }
    .nav-badge { display: none; }

    .search-container {
        flex-direction: column;
        align-items: stretch;
        padding: 1rem;
        gap: 0.75rem;
    }
    .search-icon { display: none; }
    .search-container input {
        text-align: center;
        padding: 0.5rem 0;
        border-bottom: 1px solid var(--border);
        border-radius: 0;
    }
    .search-container .btn-primary { width: 100%; border-radius: var(--radius-card); }

    .trust-bar {
        gap: 1rem;
        padding: 1rem 1.25rem;
        flex-wrap: wrap;
        justify-content: center;
    }
    .trust-item strong { font-size: 1.3rem; }

    .steps-grid {
        grid-template-columns: 1fr;
    }
    .steps-grid::before { display: none; }

    .platforms-featured { grid-template-columns: 1fr; }
    .features-grid { grid-template-columns: 1fr; }

    .content-layout,
    .content-layout--reverse {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    .content-layout--reverse .content-text { order: 1; }
    .content-layout--reverse .content-visual { order: 2; }

    .faq-grid { grid-template-columns: 1fr; }

    .section-header h2 { font-size: 1.7rem; }
    .section-how-to, .section-platforms, .section-features, .section-content, .section-faq { padding: 3.5rem 1.25rem; }

    .result-card { padding: 1.25rem; }
    .result-layout { flex-direction: column; text-align: center; }
    .thumbnail-wrapper { width: 100%; height: auto; aspect-ratio: 16/9; }
    .action-buttons { flex-direction: column; width: 100%; }
    .action-buttons > * { width: 100%; }
    .video-meta { justify-content: center; }

    .cta-banner { padding: 2.5rem 1.75rem; }
    .cta-content h2 { font-size: 1.55rem; }
    .cta-decoration { display: none; }

    .footer-links-groups { flex-direction: column; gap: 1.5rem; }
}

/* ============================================================
   In-page Video Converter
   ============================================================ */
.converter-panel {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-card);
    box-shadow: var(--shadow);
    padding: 2.5rem;
    margin: -2rem auto 4rem;
    max-width: var(--container-narrow);
}

.converter-head {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 1rem;
    margin-bottom: 1.75rem;
}
.converter-kicker {
    display: inline-block;
    font-size: 0.78rem;
    font-weight: 700;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    color: var(--primary);
    margin-bottom: 0.5rem;
}
.converter-head h2 {
    font-size: 1.55rem;
    font-weight: 800;
    color: var(--black);
    letter-spacing: -0.01em;
    margin-bottom: 0.5rem;
    line-height: 1.3;
}
.converter-lead {
    font-size: 0.92rem;
    color: var(--text-secondary);
    line-height: 1.6;
    max-width: 60ch;
}
.converter-close {
    flex-shrink: 0;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    border: none;
    background: var(--bg);
    color: var(--text-secondary);
    font-size: 1.4rem;
    line-height: 1;
    cursor: pointer;
    transition: all 0.2s ease;
}
.converter-close:hover { background: var(--border); color: var(--black); }

/* Dropzone */
.dropzone {
    border: 2px dashed var(--border);
    border-radius: var(--radius-md);
    padding: 3rem 2rem;
    text-align: center;
    color: var(--text-secondary);
    cursor: pointer;
    transition: all 0.2s ease;
    outline: none;
}
.dropzone:hover,
.dropzone:focus-visible,
.dropzone.drag {
    border-color: var(--primary);
    background: var(--primary-light);
    color: var(--primary);
}
.dropzone svg { color: var(--primary); margin-bottom: 1rem; }
.dropzone-title {
    font-size: 1.05rem;
    font-weight: 600;
    color: var(--black);
    margin-bottom: 0.4rem;
}
.dropzone-link { color: var(--primary); text-decoration: underline; }
.dropzone-hint { font-size: 0.85rem; }

/* Settings */
.converter-settings { margin-top: 1.5rem; }
.converter-file-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1rem;
    padding: 1rem 1.25rem;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    margin-bottom: 1.5rem;
}
.converter-file-info { display: flex; flex-direction: column; min-width: 0; }
.converter-file-name {
    font-weight: 600;
    color: var(--black);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}
.converter-file-size { font-size: 0.85rem; color: var(--text-secondary); }

.settings-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
    margin-bottom: 1.5rem;
}
.settings-field { display: flex; flex-direction: column; gap: 0.4rem; }
.settings-label { font-size: 0.8rem; font-weight: 600; color: var(--text-secondary); }
.settings-field select {
    font-family: inherit;
    font-size: 0.92rem;
    color: var(--text);
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 0.6rem 0.75rem;
    cursor: pointer;
    transition: border-color 0.2s ease;
}
.settings-field select:focus { outline: none; border-color: var(--primary); }

.converter-actions { display: flex; justify-content: flex-start; }

/* Progress */
.converter-progress { margin-top: 1.5rem; }
.progress-top {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 0.6rem;
}
.progress-label { font-weight: 700; color: var(--black); font-size: 1rem; }
.progress-bar {
    height: 10px;
    background: var(--border-light);
    border-radius: var(--radius-pill);
    overflow: hidden;
    margin-bottom: 1.25rem;
}
.progress-bar-fill {
    height: 100%;
    background: linear-gradient(90deg, var(--primary) 0%, var(--purple) 100%);
    border-radius: var(--radius-pill);
    transition: width 0.3s ease;
}
.log-list {
    max-height: 160px;
    overflow-y: auto;
    background: #0f1117;
    border-radius: var(--radius);
    padding: 0.85rem 1rem;
    font-family: "SF Mono", "Fira Code", "Consolas", monospace;
    font-size: 0.78rem;
    line-height: 1.5;
}
.log-line { color: rgba(255, 255, 255, 0.65); }
.log-line:last-child { color: #fff; }

/* Result */
.converter-result { margin-top: 1.5rem; }
.result-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0.75rem;
    margin-bottom: 1.5rem;
}
.result-stat {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    padding: 1rem;
    text-align: center;
}
.result-stat-label {
    display: block;
    font-size: 0.75rem;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.04em;
    margin-bottom: 0.3rem;
}
.result-stat-value { display: block; font-size: 1.2rem; font-weight: 700; color: var(--black); }
.result-stat:nth-child(3) .result-stat-value { color: var(--success); }

.result-video {
    width: 100%;
    max-height: 420px;
    background: #000;
    border-radius: var(--radius-md);
    margin-bottom: 1.5rem;
}
.result-actions { display: flex; gap: 1rem; flex-wrap: wrap; }

/* Error */
.converter-error {
    margin-top: 1.5rem;
    padding: 1.5rem;
    background: rgba(244, 95, 109, 0.08);
    border: 1px solid rgba(244, 95, 109, 0.3);
    border-radius: var(--radius-md);
    text-align: center;
}
.converter-error p { color: var(--failure); font-weight: 500; margin-bottom: 1rem; }

.btn-secondary.small {
    padding: 0.5rem 1rem;
    font-size: 0.85rem;
}

/* Converter responsive */
@media (max-width: 768px) {
    .converter-panel { padding: 1.75rem 1.25rem; margin-top: -1rem; }
    .converter-head h2 { font-size: 1.3rem; }
    .settings-grid { grid-template-columns: 1fr; }
    .result-stats { grid-template-columns: 1fr; }
    .result-actions { flex-direction: column; }
    .result-actions > * { width: 100%; }
}

/* ============================================================
   SEO Content Sections (how-to, formats, comparison, FAQ)
   ============================================================ */
.hero-badge {
    display: inline-block;
    background: var(--primary-light);
    color: var(--primary-dark);
    font-size: 0.82rem;
    font-weight: 600;
    padding: 0.4rem 0.9rem;
    border-radius: var(--radius-pill);
    margin-bottom: 1.25rem;
}
.hero-trust {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 0.75rem 1.5rem;
    margin-top: 1.75rem;
    color: var(--text-secondary);
    font-size: 0.88rem;
    font-weight: 500;
}
.hero-trust span { white-space: nowrap; }

.content-section {
    max-width: var(--container-narrow);
    margin: 0 auto 4.5rem;
    padding: 0 0.5rem;
}
.section-head { text-align: center; margin-bottom: 2.5rem; }
.section-kicker {
    display: inline-block;
    font-size: 0.78rem;
    font-weight: 700;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--primary);
    margin-bottom: 0.5rem;
}
.section-head h2 {
    font-size: 1.9rem;
    font-weight: 800;
    color: var(--black);
    letter-spacing: -0.01em;
    line-height: 1.25;
    margin-bottom: 0.75rem;
}
.section-lead {
    font-size: 1.02rem;
    color: var(--text-secondary);
    max-width: 62ch;
    margin: 0 auto;
    line-height: 1.65;
}

/* How-to steps */
.steps-grid {
    list-style: none;
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 1.25rem;
    counter-reset: step;
}
.step-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-card);
    padding: 1.75rem 1.5rem;
    position: relative;
}
.step-num {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: var(--primary);
    color: var(--white);
    font-weight: 700;
    font-size: 1rem;
    margin-bottom: 1rem;
}
.step-card h3 { font-size: 1.05rem; font-weight: 700; color: var(--black); margin-bottom: 0.5rem; }
.step-card p { font-size: 0.9rem; color: var(--text-secondary); line-height: 1.6; }

/* Format + comparison tables */
.format-table-wrap {
    overflow-x: auto;
    border: 1px solid var(--border);
    border-radius: var(--radius-card);
    background: var(--surface);
}
.format-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.92rem;
    min-width: 540px;
}
.format-table thead th {
    background: var(--bg);
    color: var(--text);
    font-weight: 700;
    text-align: left;
    padding: 0.95rem 1.25rem;
    border-bottom: 1px solid var(--border);
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.03em;
}
.format-table tbody td {
    padding: 0.85rem 1.25rem;
    border-bottom: 1px solid var(--border-light);
    color: var(--text);
}
.format-table tbody tr:last-child td { border-bottom: none; }
.format-table tbody tr:hover { background: var(--primary-light); }
.compare-table .format-table tbody td:nth-child(2) {
    color: var(--primary-dark);
    font-weight: 600;
}
.section-note {
    margin-top: 1.25rem;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

/* Prose section (What is MP4) */
.prose-section p {
    font-size: 1rem;
    color: var(--text);
    line-height: 1.75;
    margin-bottom: 1.1rem;
    max-width: 72ch;
}
.prose-section code {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 0.1rem 0.35rem;
    font-family: "SF Mono", "Fira Code", "Consolas", monospace;
    font-size: 0.85em;
    color: var(--primary-dark);
}

/* FAQ */
.faq-list { max-width: 760px; margin: 0 auto; }
.faq-item {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    margin-bottom: 0.85rem;
    overflow: hidden;
}
.faq-item summary {
    cursor: pointer;
    padding: 1.1rem 1.4rem;
    font-weight: 600;
    color: var(--black);
    font-size: 1rem;
    list-style: none;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1rem;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-item summary::after {
    content: "+";
    font-size: 1.4rem;
    color: var(--primary);
    font-weight: 400;
    line-height: 1;
    transition: transform 0.2s ease;
}
.faq-item[open] summary::after { content: "−"; }
.faq-item summary:hover { background: var(--bg); }
.faq-item p {
    padding: 0 1.4rem 1.25rem;
    color: var(--text-secondary);
    line-height: 1.65;
    font-size: 0.95rem;
}

/* Privacy banner upgrade */
.compliance-banner h2 {
    font-size: 1.4rem;
    font-weight: 800;
    color: var(--black);
    margin-bottom: 0.6rem;
}

/* Content sections responsive */
@media (max-width: 768px) {
    .section-head h2 { font-size: 1.5rem; }
    .steps-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 520px) {
    .steps-grid { grid-template-columns: 1fr; }
    .hero-trust { flex-direction: column; gap: 0.5rem; }
}