/* ===========================
   51吃瓜 主样式文件
   霓虹粉蓝渐变 · 赛博潮流风
=========================== */

:root {
    --neon-pink: #ff007f;
    --neon-cyan: #00f0ff;
    --neon-purple: #a855f7;
    --bg-white: #f8f9fa;
    --bg-light: #ffffff;
    --text-dark: #1a1a2e;
    --text-gray: #666;
    --shadow-neon: 0 0 20px rgba(255,0,127,0.3), 0 0 40px rgba(0,240,255,0.2);
    --gradient-main: linear-gradient(135deg, #ff007f, #a855f7, #00f0ff);
    --gradient-card: linear-gradient(135deg, rgba(255,0,127,0.05), rgba(0,240,255,0.05));
}

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

html { scroll-behavior: smooth; }

body {
    font-family: 'PingFang SC', 'Microsoft YaHei', 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--bg-white);
    color: var(--text-dark);
    line-height: 1.7;
    overflow-x: hidden;
}

/* ===== 滚动条 ===== */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: #f1f1f1; }
::-webkit-scrollbar-thumb { background: var(--gradient-main); border-radius: 3px; }

/* ===== 顶部导航 ===== */
header {
    background: rgba(255,255,255,0.97);
    backdrop-filter: blur(10px);
    box-shadow: 0 2px 20px rgba(0,0,0,0.08);
    padding: 0 5%;
    position: sticky;
    top: 0;
    z-index: 1000;
    border-bottom: 2px solid transparent;
    border-image: var(--gradient-main) 1;
}

.header-inner {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
}

.logo img {
    height: 42px;
    width: auto;
}

.logo-text {
    font-size: 1.4em;
    font-weight: 900;
    background: var(--gradient-main);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    letter-spacing: 1px;
}

nav ul {
    list-style: none;
    display: flex;
    gap: 5px;
}

nav ul li a {
    text-decoration: none;
    color: var(--text-dark);
    font-weight: 600;
    font-size: 0.92em;
    padding: 8px 14px;
    border-radius: 20px;
    transition: all 0.3s ease;
    white-space: nowrap;
}

nav ul li a:hover,
nav ul li a.active {
    background: var(--gradient-main);
    color: white;
    box-shadow: 0 4px 15px rgba(255,0,127,0.3);
}

/* ===== 搜索框 ===== */
.search-wrap {
    background: linear-gradient(135deg, rgba(255,0,127,0.08), rgba(0,240,255,0.08));
    padding: 14px 5%;
    display: flex;
    justify-content: center;
    border-bottom: 1px solid rgba(0,240,255,0.2);
}

.search-box {
    display: flex;
    width: 100%;
    max-width: 600px;
    border-radius: 30px;
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(255,0,127,0.15);
    border: 2px solid transparent;
    background: white;
    background-clip: padding-box;
    position: relative;
}

.search-box::before {
    content: '';
    position: absolute;
    inset: -2px;
    border-radius: 32px;
    background: var(--gradient-main);
    z-index: -1;
}

.search-box input {
    flex: 1;
    padding: 12px 20px;
    border: none;
    outline: none;
    font-size: 0.95em;
    color: var(--text-dark);
    background: white;
}

.search-box button {
    padding: 12px 28px;
    background: var(--gradient-main);
    color: white;
    border: none;
    cursor: pointer;
    font-weight: 700;
    font-size: 0.95em;
    transition: opacity 0.3s;
    white-space: nowrap;
}

.search-box button:hover { opacity: 0.9; }

/* ===== 首屏Banner ===== */
.banner {
    position: relative;
    height: 560px;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
}

.banner-bg {
    position: absolute;
    inset: 0;
    background: url('/images/banner-bg.jpg') center/cover no-repeat;
    filter: brightness(0.6);
    transform: scale(1.05);
    animation: slowZoom 20s ease-in-out infinite alternate;
}

@keyframes slowZoom {
    from { transform: scale(1.05); }
    to { transform: scale(1.12); }
}

.banner-overlay {
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, rgba(255,0,127,0.3) 0%, rgba(10,10,30,0.5) 50%, rgba(0,240,255,0.3) 100%);
}

.banner-particles {
    position: absolute;
    inset: 0;
    overflow: hidden;
}

.particle {
    position: absolute;
    width: 4px;
    height: 4px;
    border-radius: 50%;
    background: var(--neon-cyan);
    animation: float linear infinite;
    opacity: 0.6;
}

@keyframes float {
    0% { transform: translateY(100vh) rotate(0deg); opacity: 0; }
    10% { opacity: 0.6; }
    90% { opacity: 0.6; }
    100% { transform: translateY(-100px) rotate(720deg); opacity: 0; }
}

.banner-content {
    position: relative;
    z-index: 2;
    text-align: center;
    color: white;
    padding: 0 20px;
    max-width: 900px;
}

.banner-content h1 {
    font-size: 3.2em;
    font-weight: 900;
    margin-bottom: 15px;
    text-shadow: 0 0 30px rgba(255,0,127,0.8), 0 0 60px rgba(0,240,255,0.5);
    letter-spacing: 2px;
    line-height: 1.2;
}

.banner-content .subtitle {
    font-size: 1.2em;
    margin-bottom: 30px;
    opacity: 0.9;
    text-shadow: 0 2px 10px rgba(0,0,0,0.5);
}

.banner-btns {
    display: flex;
    gap: 15px;
    justify-content: center;
    flex-wrap: wrap;
}

.btn-primary {
    padding: 14px 36px;
    background: var(--gradient-main);
    color: white;
    border: none;
    border-radius: 30px;
    font-size: 1.05em;
    font-weight: 700;
    cursor: pointer;
    text-decoration: none;
    display: inline-block;
    box-shadow: 0 6px 25px rgba(255,0,127,0.5);
    transition: all 0.3s ease;
    letter-spacing: 1px;
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 35px rgba(255,0,127,0.7);
}

.btn-outline {
    padding: 14px 36px;
    background: transparent;
    color: white;
    border: 2px solid var(--neon-cyan);
    border-radius: 30px;
    font-size: 1.05em;
    font-weight: 700;
    cursor: pointer;
    text-decoration: none;
    display: inline-block;
    transition: all 0.3s ease;
    box-shadow: 0 0 15px rgba(0,240,255,0.3);
    letter-spacing: 1px;
}

.btn-outline:hover {
    background: rgba(0,240,255,0.15);
    transform: translateY(-3px);
    box-shadow: 0 0 30px rgba(0,240,255,0.6);
}

/* ===== 通用 Section 样式 ===== */
.section {
    padding: 80px 5%;
}

.section-alt {
    background: linear-gradient(135deg, rgba(255,0,127,0.03), rgba(0,240,255,0.03));
}

.section-title {
    text-align: center;
    margin-bottom: 50px;
}

.section-title h2 {
    font-size: 2.4em;
    font-weight: 900;
    color: var(--text-dark);
    position: relative;
    display: inline-block;
    margin-bottom: 12px;
}

.section-title h2 .brand {
    background: var(--gradient-main);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.section-title h2::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: var(--gradient-main);
    border-radius: 2px;
}

.section-title p {
    color: var(--text-gray);
    font-size: 1.05em;
    margin-top: 18px;
}

/* ===== 视频卡片网格 ===== */
.video-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 25px;
}

.video-card {
    background: white;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 5px 20px rgba(0,0,0,0.06);
    transition: all 0.3s ease;
    border: 1px solid rgba(0,240,255,0.1);
}

.video-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 15px 40px rgba(255,0,127,0.15), 0 0 0 1px rgba(0,240,255,0.3);
}

.video-thumb {
    position: relative;
    height: 170px;
    overflow: hidden;
    background: #111;
    cursor: pointer;
}

.video-thumb img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.4s ease;
    display: block;
}

.video-card:hover .video-thumb img {
    transform: scale(1.08);
}

.play-overlay {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(0,0,0,0.3);
    opacity: 0;
    transition: opacity 0.3s ease;
}

.video-card:hover .play-overlay {
    opacity: 1;
}

.play-icon {
    width: 56px;
    height: 56px;
    background: rgba(255,255,255,0.9);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 0 20px rgba(255,0,127,0.6), 0 0 40px rgba(0,240,255,0.4);
    animation: pulsePlay 1.5s ease-in-out infinite;
}

@keyframes pulsePlay {
    0%, 100% { transform: scale(1); box-shadow: 0 0 20px rgba(255,0,127,0.6); }
    50% { transform: scale(1.1); box-shadow: 0 0 35px rgba(255,0,127,0.9), 0 0 60px rgba(0,240,255,0.5); }
}

.play-icon::after {
    content: '';
    border-left: 20px solid var(--neon-pink);
    border-top: 12px solid transparent;
    border-bottom: 12px solid transparent;
    margin-left: 4px;
}

.video-badge {
    position: absolute;
    top: 10px;
    left: 10px;
    background: var(--gradient-main);
    color: white;
    padding: 3px 10px;
    border-radius: 10px;
    font-size: 0.75em;
    font-weight: 700;
}

.video-duration {
    position: absolute;
    bottom: 10px;
    right: 10px;
    background: rgba(0,0,0,0.7);
    color: white;
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 0.8em;
}

.video-info {
    padding: 16px;
}

.video-info h3 {
    font-size: 1em;
    font-weight: 700;
    margin-bottom: 8px;
    color: var(--text-dark);
    line-height: 1.4;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.video-stats {
    display: flex;
    gap: 12px;
    color: var(--text-gray);
    font-size: 0.82em;
}

.video-stats span {
    display: flex;
    align-items: center;
    gap: 3px;
}

/* ===== 社区弹幕 ===== */
.community-section {
    background: linear-gradient(135deg, #0a0a1e, #1a0a2e);
    color: white;
    padding: 80px 5%;
    overflow: hidden;
    position: relative;
}

.community-section .section-title h2 {
    color: white;
}

.danmu-track {
    position: relative;
    height: 50px;
    overflow: hidden;
    margin: 10px 0;
}

.danmu-item {
    position: absolute;
    white-space: nowrap;
    padding: 6px 16px;
    border-radius: 20px;
    font-size: 0.9em;
    font-weight: 600;
    animation: danmuScroll linear infinite;
    top: 50%;
    transform: translateY(-50%);
}

.danmu-item:nth-child(odd) {
    background: rgba(255,0,127,0.2);
    border: 1px solid rgba(255,0,127,0.4);
    color: #ffb3d9;
}

.danmu-item:nth-child(even) {
    background: rgba(0,240,255,0.15);
    border: 1px solid rgba(0,240,255,0.3);
    color: #b3f5ff;
}

@keyframes danmuScroll {
    from { left: 100%; }
    to { left: -100%; }
}

.topic-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    justify-content: center;
    margin-top: 30px;
}

.topic-tag {
    padding: 8px 20px;
    border-radius: 20px;
    background: rgba(255,255,255,0.08);
    border: 1px solid rgba(255,255,255,0.15);
    color: white;
    font-size: 0.9em;
    cursor: pointer;
    transition: all 0.3s;
}

.topic-tag:hover {
    background: var(--gradient-main);
    border-color: transparent;
    box-shadow: 0 4px 15px rgba(255,0,127,0.4);
}

/* ===== AI模块 ===== */
.ai-tools-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    gap: 20px;
}

.ai-tool-card {
    background: white;
    border-radius: 16px;
    padding: 30px 24px;
    text-align: center;
    border: 1px solid rgba(0,240,255,0.15);
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}

.ai-tool-card::before {
    content: '';
    position: absolute;
    top: 0; left: 0; right: 0;
    height: 3px;
    background: var(--gradient-main);
}

.ai-tool-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0,240,255,0.15);
    border-color: rgba(0,240,255,0.4);
}

.ai-icon {
    font-size: 2.5em;
    margin-bottom: 15px;
    display: block;
}

.ai-tool-card h3 {
    font-size: 1.1em;
    font-weight: 700;
    margin-bottom: 8px;
    color: var(--text-dark);
}

.ai-tool-card p {
    color: var(--text-gray);
    font-size: 0.88em;
    line-height: 1.6;
}

/* ===== 专家模块 ===== */
.experts-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(220px, 1fr));
    gap: 25px;
}

.expert-card {
    background: white;
    border-radius: 16px;
    padding: 30px 20px;
    text-align: center;
    box-shadow: 0 5px 20px rgba(0,0,0,0.06);
    transition: all 0.3s ease;
    border: 1px solid rgba(255,0,127,0.1);
}

.expert-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(255,0,127,0.12);
}

.expert-avatar {
    width: 90px;
    height: 90px;
    border-radius: 50%;
    object-fit: cover;
    margin: 0 auto 15px;
    display: block;
    border: 3px solid transparent;
    background: var(--gradient-main) border-box;
    box-shadow: 0 0 0 3px white, 0 0 0 5px;
    outline: 3px solid;
    outline-offset: 2px;
    outline-color: var(--neon-pink);
}

.expert-card h3 {
    font-size: 1.05em;
    font-weight: 700;
    margin-bottom: 5px;
}

.expert-card .role {
    color: var(--neon-pink);
    font-size: 0.85em;
    font-weight: 600;
    margin-bottom: 10px;
}

.expert-card p {
    color: var(--text-gray);
    font-size: 0.85em;
    line-height: 1.6;
}

/* ===== 用户评价 ===== */
.reviews-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
}

.review-card {
    background: white;
    border-radius: 16px;
    padding: 24px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.05);
    border-left: 4px solid var(--neon-cyan);
    transition: all 0.3s ease;
    position: relative;
}

.review-card::before {
    content: '"';
    position: absolute;
    top: 10px;
    right: 20px;
    font-size: 4em;
    color: rgba(0,240,255,0.15);
    font-family: Georgia, serif;
    line-height: 1;
}

.review-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(0,240,255,0.12);
}

.review-stars {
    color: #ffd700;
    font-size: 1em;
    margin-bottom: 10px;
}

.review-text {
    color: var(--text-dark);
    font-size: 0.95em;
    line-height: 1.7;
    margin-bottom: 15px;
}

.review-author {
    display: flex;
    align-items: center;
    gap: 10px;
}

.review-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--gradient-main);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-weight: 700;
    font-size: 1em;
    flex-shrink: 0;
}

.review-name {
    font-weight: 700;
    font-size: 0.9em;
    color: var(--text-dark);
}

.review-date {
    font-size: 0.8em;
    color: var(--text-gray);
}

/* ===== 合作伙伴 ===== */
.partners-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    justify-content: center;
    align-items: center;
}

.partner-item {
    background: white;
    border-radius: 12px;
    padding: 18px 30px;
    font-weight: 700;
    color: var(--text-gray);
    font-size: 1em;
    box-shadow: 0 3px 15px rgba(0,0,0,0.05);
    transition: all 0.3s;
    border: 1px solid rgba(0,240,255,0.1);
}

.partner-item:hover {
    color: var(--neon-pink);
    border-color: rgba(255,0,127,0.3);
    box-shadow: 0 5px 20px rgba(255,0,127,0.1);
}

/* ===== FAQ ===== */
.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    background: white;
    border-radius: 12px;
    margin-bottom: 12px;
    overflow: hidden;
    box-shadow: 0 3px 15px rgba(0,0,0,0.04);
    border: 1px solid rgba(0,240,255,0.1);
}

.faq-question {
    padding: 20px 24px;
    cursor: pointer;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-weight: 700;
    font-size: 0.98em;
    color: var(--text-dark);
    transition: background 0.3s;
}

.faq-question:hover {
    background: linear-gradient(135deg, rgba(255,0,127,0.04), rgba(0,240,255,0.04));
}

.faq-question .faq-icon {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    background: var(--gradient-main);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.1em;
    flex-shrink: 0;
    transition: transform 0.3s;
}

.faq-item.open .faq-icon {
    transform: rotate(45deg);
}

.faq-answer {
    padding: 0 24px;
    max-height: 0;
    overflow: hidden;
    transition: all 0.3s ease;
    color: var(--text-gray);
    font-size: 0.93em;
    line-height: 1.7;
}

.faq-item.open .faq-answer {
    padding: 0 24px 20px;
    max-height: 200px;
}

/* ===== 联系模块 ===== */
.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 30px;
    max-width: 900px;
    margin: 0 auto;
}

.contact-card {
    background: white;
    border-radius: 16px;
    padding: 30px;
    text-align: center;
    box-shadow: 0 5px 20px rgba(0,0,0,0.06);
    border-top: 3px solid var(--neon-cyan);
}

.contact-icon {
    font-size: 2.5em;
    margin-bottom: 15px;
    display: block;
}

.contact-card h3 {
    font-size: 1.1em;
    font-weight: 700;
    margin-bottom: 10px;
}

.contact-card p, .contact-card a {
    color: var(--text-gray);
    font-size: 0.9em;
    text-decoration: none;
    line-height: 1.8;
}

.contact-card a:hover { color: var(--neon-pink); }

/* ===== 页脚 ===== */
footer {
    background: linear-gradient(135deg, #0a0a1e, #1a0a2e);
    color: rgba(255,255,255,0.7);
    padding: 60px 5% 30px;
}

.footer-top {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-brand .logo-text {
    font-size: 1.6em;
    display: block;
    margin-bottom: 12px;
}

.footer-brand p {
    font-size: 0.88em;
    line-height: 1.8;
    color: rgba(255,255,255,0.5);
}

.footer-col h4 {
    color: white;
    font-size: 1em;
    font-weight: 700;
    margin-bottom: 15px;
    position: relative;
    padding-bottom: 10px;
}

.footer-col h4::after {
    content: '';
    position: absolute;
    bottom: 0; left: 0;
    width: 30px;
    height: 2px;
    background: var(--gradient-main);
}

.footer-col ul {
    list-style: none;
}

.footer-col ul li {
    margin-bottom: 8px;
}

.footer-col ul li a {
    color: rgba(255,255,255,0.5);
    text-decoration: none;
    font-size: 0.88em;
    transition: color 0.3s;
}

.footer-col ul li a:hover { color: var(--neon-cyan); }

.footer-bottom {
    border-top: 1px solid rgba(255,255,255,0.1);
    padding-top: 25px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 15px;
    font-size: 0.85em;
}

.footer-bottom a {
    color: rgba(255,255,255,0.5);
    text-decoration: none;
    transition: color 0.3s;
}

.footer-bottom a:hover { color: var(--neon-cyan); }

.footer-social {
    display: flex;
    gap: 12px;
}

.social-btn {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    background: rgba(255,255,255,0.08);
    border: 1px solid rgba(255,255,255,0.15);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 0.85em;
    text-decoration: none;
    transition: all 0.3s;
}

.social-btn:hover {
    background: var(--gradient-main);
    border-color: transparent;
    box-shadow: 0 4px 15px rgba(255,0,127,0.4);
}

/* ===== 内页面包屑 ===== */
.breadcrumb {
    padding: 15px 5%;
    background: white;
    border-bottom: 1px solid rgba(0,240,255,0.1);
    font-size: 0.88em;
    color: var(--text-gray);
}

.breadcrumb a {
    color: var(--neon-pink);
    text-decoration: none;
}

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

/* ===== 内页Banner ===== */
.inner-banner {
    background: linear-gradient(135deg, #0a0a1e, #1a0a2e);
    padding: 60px 5%;
    text-align: center;
    color: white;
    position: relative;
    overflow: hidden;
}

.inner-banner::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle at center, rgba(255,0,127,0.15) 0%, transparent 60%);
    animation: rotateBg 15s linear infinite;
}

@keyframes rotateBg {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

.inner-banner h1 {
    font-size: 2.5em;
    font-weight: 900;
    margin-bottom: 12px;
    position: relative;
    z-index: 1;
    text-shadow: 0 0 20px rgba(255,0,127,0.5);
}

.inner-banner p {
    font-size: 1.05em;
    opacity: 0.8;
    position: relative;
    z-index: 1;
}

/* ===== 统计数字 ===== */
.stats-bar {
    background: var(--gradient-main);
    padding: 30px 5%;
    display: flex;
    justify-content: space-around;
    flex-wrap: wrap;
    gap: 20px;
}

.stat-item {
    text-align: center;
    color: white;
}

.stat-num {
    font-size: 2.2em;
    font-weight: 900;
    display: block;
    line-height: 1;
}

.stat-label {
    font-size: 0.88em;
    opacity: 0.85;
    margin-top: 5px;
    display: block;
}

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
    .footer-top { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
    .header-inner { flex-wrap: wrap; height: auto; padding: 12px 0; gap: 10px; }
    nav ul { flex-wrap: wrap; justify-content: center; gap: 3px; }
    nav ul li a { padding: 6px 10px; font-size: 0.82em; }
    .banner { height: 420px; }
    .banner-content h1 { font-size: 2em; }
    .footer-top { grid-template-columns: 1fr; gap: 25px; }
    .footer-bottom { flex-direction: column; text-align: center; }
    .section { padding: 50px 5%; }
    .section-title h2 { font-size: 1.8em; }
}

@media (max-width: 480px) {
    .banner-content h1 { font-size: 1.6em; }
    .banner-btns { flex-direction: column; align-items: center; }
    .video-grid { grid-template-columns: 1fr; }
}