/* Telegram 中文官网 高仿样式 */
:root {
    --tg-blue: #24A1DE;
    --tg-dark-blue: #1c8ac0;
    --text-main: #222;
    --text-gray: #707579;
    --bg-light: #f4f4f5;
    --header-height: 64px;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: #fff;
    color: var(--text-main);
    line-height: 1.6;
}

/* Header */
header {
    height: var(--header-height);
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 10%;
    position: sticky;
    top: 0;
    background: #fff;
    z-index: 100;
}

.header-left {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo-img {
    width: 32px;
    height: 32px;
}

.brand-name {
    font-weight: bold;
    font-size: 16px;
    color: var(--tg-blue);
}

nav {
    display: flex;
    gap: 30px;
}

nav a {
    text-decoration: none;
    color: var(--text-main);
    font-size: 14px;
    transition: color 0.2s;
}

nav a:hover, nav a.active {
    color: var(--tg-blue);
}

.header-right {
    display: flex;
    align-items: center;
    gap: 20px;
}

.btn-mini {
    background: var(--tg-blue);
    color: #fff;
    padding: 6px 15px;
    border-radius: 20px;
    text-decoration: none;
    font-size: 13px;
    display: flex;
    align-items: center;
    gap: 5px;
}

/* Hero Section */
.hero {
    text-align: center;
    padding: 60px 20px;
    max-width: 1200px;
    margin: 0 auto;
}

.mockup-container {
    margin-bottom: 40px;
}

.mockup-img {
    max-width: 100%;
    width: 600px;
    height: auto;
}

.hero h1 {
    font-size: 32px;
    margin-bottom: 10px;
    font-weight: 500;
}

.hero .subtitle {
    color: var(--text-gray);
    font-size: 16px;
    margin-bottom: 40px;
}

.download-btn-large {
    background: var(--tg-blue);
    color: #fff;
    padding: 15px 40px;
    border-radius: 30px;
    text-decoration: none;
    font-size: 18px;
    display: inline-block;
    margin-bottom: 20px;
    transition: background 0.2s;
}

.download-btn-large:hover {
    background: var(--tg-dark-blue);
}

.all-platforms {
    color: var(--tg-blue);
    text-decoration: none;
    font-size: 14px;
    display: block;
    margin-bottom: 60px;
}

.hero-footer-links {
    font-size: 13px;
    color: var(--text-gray);
}

.hero-footer-links a {
    color: var(--tg-blue);
    text-decoration: none;
}

/* Footer */
footer {
    border-top: 1px solid #eee;
    padding: 60px 10% 40px;
    margin-top: 100px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr 1fr 1.5fr;
    gap: 40px;
    margin-bottom: 60px;
}

.footer-col h4 {
    font-size: 15px;
    margin-bottom: 20px;
    font-weight: 600;
}

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

.footer-col ul li {
    margin-bottom: 10px;
}

.footer-col ul li a {
    text-decoration: none;
    color: var(--text-gray);
    font-size: 14px;
}

.footer-col p {
    font-size: 13px;
    color: var(--text-gray);
    margin-bottom: 15px;
}

.qr-section {
    text-align: center;
}

.qr-code {
    width: 100px;
    height: 100px;
    margin-bottom: 10px;
}

.copyright {
    text-align: center;
    font-size: 12px;
    color: #aaa;
    border-top: 1px solid #f9f9f9;
    padding-top: 20px;
}

/* Mobile Responsive */
@media (max-width: 768px) {
    header {
        padding: 0 5%;
    }
    nav {
        display: none;
    }
    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }
    .hero h1 {
        font-size: 24px;
    }
}