/*
 * kuaiwilian.com.cn  -  avbobo播放器官方网站
 * 全局样式表
 * 说明：统一视觉风格、响应式布局、SEO友好
 */

/* ===== 基础重置 ===== */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html, body {
    font-family: "PingFang SC", "Microsoft YaHei", "Source Han Sans SC", sans-serif;
    color: #2c3e50;
    background-color: #f7f9fc;
    line-height: 1.75;
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    color: #2b6cb0;
    text-decoration: none;
    transition: color .2s ease;
}

a:hover { color: #1a4c8c; }

ul, ol { list-style: none; }

h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    color: #1a202c;
    line-height: 1.4;
}

h1 { font-size: 2.2rem; }
h2 { font-size: 1.7rem; }
h3 { font-size: 1.3rem; }
p  { margin-bottom: 1rem; }

/* ===== 布局容器 ===== */
.container {
    width: 100%;
    max-width: 1180px;
    margin: 0 auto;
    padding: 0 20px;
}

section { padding: 70px 0; }

.section-title {
    text-align: center;
    margin-bottom: 48px;
}
.section-title h2 {
    position: relative;
    display: inline-block;
    padding-bottom: 12px;
}
.section-title h2::after {
    content: "";
    position: absolute;
    left: 50%;
    bottom: 0;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: linear-gradient(90deg, #2b6cb0, #38a169);
    border-radius: 2px;
}
.section-title p {
    color: #6b7280;
    margin-top: 14px;
    font-size: 1.02rem;
}

/* ===== 导航栏 ===== */
.header {
    background: #ffffff;
    box-shadow: 0 2px 12px rgba(0, 0, 0, .06);
    position: sticky;
    top: 0;
    z-index: 999;
}
.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 70px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 1.25rem;
    color: #2b6cb0;
}
.logo-icon {
    width: 36px;
    height: 36px;
    background: linear-gradient(135deg, #2b6cb0, #38a169);
    border-radius: 8px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 18px;
    font-weight: 700;
}

.nav { display: flex; gap: 30px; }
.nav a {
    font-size: 1rem;
    color: #2d3748;
    font-weight: 500;
    padding: 6px 2px;
    border-bottom: 2px solid transparent;
}
.nav a:hover,
.nav a.active {
    color: #2b6cb0;
    border-bottom-color: #2b6cb0;
}

.mobile-menu-btn {
    display: none;
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: #2d3748;
}

/* ===== Hero / Banner ===== */
.hero {
    background: linear-gradient(135deg, #e8f4ff 0%, #f0fff4 100%);
    padding: 90px 0 80px;
    position: relative;
    overflow: hidden;
}
.hero-inner {
    display: flex;
    align-items: center;
    gap: 50px;
}
.hero-text { flex: 1.1; }
.hero-text h1 {
    font-size: 2.6rem;
    color: #1a202c;
    margin-bottom: 18px;
    line-height: 1.3;
}
.hero-text h1 span {
    color: #2b6cb0;
}
.hero-text p {
    font-size: 1.08rem;
    color: #4a5568;
    margin-bottom: 28px;
    max-width: 540px;
}

.hero-image {
    flex: 1;
    text-align: center;
}
.hero-image img {
    border-radius: 16px;
    box-shadow: 0 20px 50px rgba(43, 108, 176, .22);
    max-width: 500px;
}

.btn {
    display: inline-block;
    padding: 12px 28px;
    border-radius: 6px;
    font-size: 1rem;
    font-weight: 600;
    text-align: center;
    cursor: pointer;
    border: none;
    transition: transform .15s ease, box-shadow .2s ease;
}
.btn-primary {
    background: linear-gradient(90deg, #2b6cb0, #3182ce);
    color: #fff;
}
.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(43,108,176,.35);
    color: #fff;
}
.btn-secondary {
    background: #fff;
    color: #2b6cb0;
    border: 1px solid #2b6cb0;
    margin-left: 12px;
}
.btn-secondary:hover {
    background: #2b6cb0;
    color: #fff;
}

/* ===== 卡片网格 ===== */
.grid-3 {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 28px;
}
.grid-4 {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.card {
    background: #fff;
    border-radius: 12px;
    padding: 30px 24px;
    box-shadow: 0 2px 12px rgba(0,0,0,.04);
    transition: transform .25s ease, box-shadow .25s ease;
    border-top: 3px solid transparent;
}
.card:hover {
    transform: translateY(-6px);
    box-shadow: 0 12px 28px rgba(0,0,0,.08);
}
.card-blue  { border-top-color: #2b6cb0; }
.card-green  { border-top-color: #38a169; }
.card-orange { border-top-color: #dd6b20; }
.card-purple { border-top-color: #805ad5; }

.card-icon {
    width: 54px;
    height: 54px;
    border-radius: 12px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 26px;
    margin-bottom: 18px;
}
.card-blue  .card-icon { background: #ebf4ff; color: #2b6cb0; }
.card-green  .card-icon { background: #f0fff4; color: #38a169; }
.card-orange .card-icon { background: #fffaeb; color: #dd6b20; }
.card-purple .card-icon { background: #faf5ff; color: #805ad5; }

.card h3 { margin-bottom: 10px; }
.card p  { color: #4a5568; font-size: .96rem; }

/* ===== 两栏布局 ===== */
.two-col {
    display: flex;
    gap: 60px;
    align-items: center;
}
.two-col > div { flex: 1; }
.two-col img { border-radius: 14px; box-shadow: 0 10px 30px rgba(0,0,0,.12); }

/* ===== 数据统计 ===== */
.stats {
    background: linear-gradient(135deg, #2b6cb0, #38a169);
    color: #fff;
    padding: 60px 0;
    text-align: center;
}
.stats .container {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 30px;
}
.stat-num {
    font-size: 2.6rem;
    font-weight: 700;
    line-height: 1.2;
}
.stat-label {
    font-size: .98rem;
    opacity: .92;
    margin-top: 6px;
}

/* ===== 页脚 ===== */
.footer {
    background: #1a202c;
    color: #e2e8f0;
    padding: 50px 0 24px;
}
.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: 40px;
    margin-bottom: 40px;
}
.footer-col h4 {
    color: #fff;
    font-size: 1.05rem;
    margin-bottom: 18px;
    padding-bottom: 10px;
    border-bottom: 1px solid rgba(255,255,255,.08);
}
.footer-col p { color: #a0aec0; font-size: .9rem; }
.footer-col ul li { margin-bottom: 8px; font-size: .9rem; }
.footer-col ul li a { color: #a0aec0; }
.footer-col ul li a:hover { color: #63b3ed; }
.footer-bottom {
    border-top: 1px solid rgba(255,255,255,.08);
    padding-top: 20px;
    text-align: center;
    color: #718096;
    font-size: .88rem;
}

/* ===== 内部页面通用 ===== */
.page-header {
    background: linear-gradient(135deg, #2b6cb0, #2c5282);
    color: #fff;
    padding: 60px 0;
    text-align: center;
}
.page-header h1 { color: #fff; margin-bottom: 10px; }
.page-header p  { opacity: .92; }

/* ===== 表格 ===== */
.table-wrap { overflow-x: auto; margin-top: 20px; }
table {
    width: 100%;
    border-collapse: collapse;
    background: #fff;
    border-radius: 10px;
    overflow: hidden;
    box-shadow: 0 2px 10px rgba(0,0,0,.04);
}
th, td {
    padding: 14px 18px;
    text-align: left;
    border-bottom: 1px solid #edf2f7;
    font-size: .95rem;
}
th {
    background: #f7fafc;
    font-weight: 600;
    color: #2d3748;
}
tr:last-child td { border-bottom: none; }
table tr:hover td { background: #fafbfc; }

/* ===== 表单 ===== */
.form-group { margin-bottom: 18px; }
.form-group label {
    display: block;
    font-weight: 500;
    margin-bottom: 6px;
    color: #2d3748;
}
.form-group input,
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 12px 14px;
    border: 1px solid #cbd5e0;
    border-radius: 6px;
    font-size: .95rem;
    font-family: inherit;
    background: #fff;
    transition: border-color .2s ease;
}
.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: #2b6cb0;
    box-shadow: 0 0 0 3px rgba(43,108,176,.15);
}
.form-group textarea { min-height: 140px; resize: vertical; }

.contact-wrap {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 50px;
}
.contact-info .info-item {
    display: flex;
    gap: 16px;
    margin-bottom: 22px;
}
.contact-info .info-icon {
    width: 46px;
    height: 46px;
    background: #ebf4ff;
    color: #2b6cb0;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 22px;
    flex-shrink: 0;
}
.contact-info h4 { margin-bottom: 4px; }
.contact-info p { color: #4a5568; font-size: .95rem; }

/* ===== 文章列表 ===== */
.news-list .news-item {
    display: flex;
    gap: 24px;
    background: #fff;
    border-radius: 12px;
    padding: 22px;
    margin-bottom: 22px;
    box-shadow: 0 2px 10px rgba(0,0,0,.04);
    transition: transform .2s ease, box-shadow .2s ease;
}
.news-list .news-item:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 22px rgba(0,0,0,.08);
}
.news-item .news-thumb {
    width: 220px;
    height: 150px;
    border-radius: 8px;
    overflow: hidden;
    flex-shrink: 0;
    background: #edf2f7;
}
.news-item .news-thumb img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}
.news-item h3 {
    font-size: 1.1rem;
    margin-bottom: 10px;
    color: #2d3748;
}
.news-item h3 a { color: inherit; }
.news-item h3 a:hover { color: #2b6cb0; }
.news-meta { color: #718096; font-size: .86rem; margin-bottom: 8px; }
.news-item p { color: #4a5568; font-size: .94rem; }

/* ===== 下载指南步骤 ===== */
.steps {
    display: flex;
    justify-content: space-between;
    position: relative;
    flex-wrap: wrap;
}
.step {
    flex: 1;
    min-width: 180px;
    text-align: center;
    position: relative;
    padding: 0 12px;
}
.step-num {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, #2b6cb0, #38a169);
    color: #fff;
    border-radius: 50%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.1rem;
    margin-bottom: 14px;
}
.step h4 { margin-bottom: 6px; }
.step p { color: #4a5568; font-size: .93rem; }

/* ===== 图标字体（简易 emoji/符号） ===== */
/* 不依赖任何外部字体库 */

/* ===== 响应式 ===== */
@media (max-width: 1024px) {
    .grid-3 { grid-template-columns: repeat(2, 1fr); }
    .grid-4 { grid-template-columns: repeat(2, 1fr); }
    .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
    .nav {
        display: none;
        position: absolute;
        top: 70px;
        left: 0;
        width: 100%;
        background: #fff;
        flex-direction: column;
        gap: 0;
        box-shadow: 0 8px 16px rgba(0,0,0,.08);
    }
    .nav.open { display: flex; }
    .nav a {
        padding: 14px 20px;
        border-bottom: 1px solid #f0f4f8;
        border-left: 3px solid transparent;
    }
    .nav a.active,
    .nav a:hover {
        border-left-color: #2b6cb0;
    }
    .mobile-menu-btn { display: block; }

    .hero-inner { flex-direction: column-reverse; }
    .hero-text h1 { font-size: 1.8rem; }
    .hero { padding: 60px 0 50px; }

    .two-col { flex-direction: column; }
    .contact-wrap { grid-template-columns: 1fr; }
    .stats .container { grid-template-columns: repeat(2, 1fr); }

    .news-list .news-item { flex-direction: column; }
    .news-item .news-thumb { width: 100%; height: 180px; }

    .step { min-width: 140px; margin-bottom: 30px; }
    .btn { display: inline-block; }
    .btn-secondary { margin-left: 0; margin-top: 10px; }

    h1 { font-size: 1.7rem; }
    h2 { font-size: 1.4rem; }

    .footer-grid { grid-template-columns: 1fr; gap: 28px; }
}

@media (max-width: 480px) {
    .grid-3 { grid-template-columns: 1fr; }
    .grid-4 { grid-template-columns: 1fr; }
    .stats .container { grid-template-columns: 1fr 1fr; }
    .hero-text h1 { font-size: 1.5rem; }
}