/* 全局变量：深色极简风 */
:root {
    --bg-dark: #0f172a;
    --bg-card: #1e293b;
    --primary-color: #3b82f6;
    --primary-hover: #2563eb;
    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --font-family: 'Inter', sans-serif;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-family);
    background-color: var(--bg-dark);
    color: var(--text-main);
    line-height: 1.6;
}

/* 按钮基础样式 */
.btn {
    display: inline-block;
    padding: 10px 24px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    cursor: pointer;
    border: none;
    text-align: center;
}

.btn-primary {
    background-color: var(--primary-color);
    color: #fff;
    box-shadow: 0 4px 14px 0 rgba(59, 130, 246, 0.39);
}

.btn-primary:hover {
    background-color: var(--primary-hover);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(59, 130, 246, 0.23);
}

.btn-secondary {
    background-color: transparent;
    color: var(--text-main);
    border: 1px solid var(--text-muted);
}

.btn-secondary:hover {
    border-color: var(--text-main);
    background-color: rgba(255, 255, 255, 0.05);
}

.btn-large {
    padding: 14px 32px;
    font-size: 1.1rem;
}

/* 导航栏 */
.navbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 5%;
    background-color: rgba(15, 23, 42, 0.85);
    backdrop-filter: blur(12px);
    position: fixed;
    width: 100%;
    top: 0;
    z-index: 1000;
    border-bottom: 1px solid rgba(255,255,255,0.05);
}

.logo {
    font-size: 1.5rem;
    font-weight: 800;
    letter-spacing: -0.5px;
    background: linear-gradient(to right, #fff, #94a3b8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.nav-right {
    display: flex;
    align-items: center;
    gap: 24px;
}

.nav-links {
    list-style: none;
    display: flex;
    gap: 24px;
}

.nav-links a {
    color: var(--text-muted);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
}

.nav-links a:hover {
    color: var(--text-main);
}

.lang-select {
    background-color: var(--bg-card);
    color: var(--text-main);
    border: 1px solid rgba(255,255,255,0.1);
    padding: 8px 12px;
    border-radius: 6px;
    outline: none;
    font-family: inherit;
    cursor: pointer;
}

/* 首屏 Hero */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 120px 20px 40px;
    background: radial-gradient(circle at 50% 0%, #1e293b 0%, #0f172a 60%);
}

.hero-content {
    max-width: 800px;
}

.hero h1 {
    font-size: 4.5rem;
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: 24px;
    letter-spacing: -1px;
}

.highlight {
    color: var(--primary-color);
}

.hero p {
    font-size: 1.25rem;
    color: var(--text-muted);
    margin-bottom: 40px;
    max-width: 650px;
    margin-left: auto;
    margin-right: auto;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    justify-content: center;
    margin-bottom: 24px;
}

.trust-badge {
    font-size: 0.95rem !important;
    color: #10b981 !important; /* 绿色表示安全/信任 */
    font-weight: 600;
}

/* 核心功能 & 定价区公用 */
.features, .pricing {
    padding: 100px 5%;
    text-align: center;
}

.section-title {
    font-size: 2.5rem;
    margin-bottom: 60px;
    font-weight: 800;
}

.feature-grid, .pricing-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 30px;
    max-width: 1200px;
    margin: 0 auto;
}

/* 功能卡片 */
.feature-card {
    background-color: var(--bg-card);
    padding: 40px 30px;
    border-radius: 16px;
    text-align: left;
    border: 1px solid rgba(255,255,255,0.05);
    transition: transform 0.3s, box-shadow 0.3s;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 30px rgba(0,0,0,0.5);
}

.feature-card .icon {
    font-size: 2.5rem;
    margin-bottom: 20px;
}

.feature-card h3 {
    margin-bottom: 15px;
    font-size: 1.4rem;
}

.feature-card p {
    color: var(--text-muted);
}

/* 定价卡片 */
.price-card {
    background-color: var(--bg-card);
    padding: 50px 40px;
    border-radius: 16px;
    border: 1px solid rgba(255,255,255,0.05);
    position: relative;
    display: flex;
    flex-direction: column;
}

.price-card.popular {
    border: 2px solid var(--primary-color);
    transform: scale(1.05);
    background: linear-gradient(180deg, rgba(30,41,59,1) 0%, rgba(15,23,42,1) 100%);
}

.badge {
    position: absolute;
    top: -14px;
    left: 50%;
    transform: translateX(-50%);
    background-color: var(--primary-color);
    color: #fff;
    padding: 6px 18px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    box-shadow: 0 4px 10px rgba(59, 130, 246, 0.4);
}

.price {
    font-size: 3.5rem;
    font-weight: 800;
    margin: 20px 0;
}

.price span {
    font-size: 1.2rem;
    color: var(--text-muted);
    font-weight: 400;
}

.price-card ul {
    list-style: none;
    margin-bottom: 40px;
    text-align: left;
    flex-grow: 1;
}

.price-card ul li {
    margin-bottom: 16px;
    color: var(--text-muted);
    display: flex;
    align-items: center;
}

.price-card ul li::before {
    content: '✓';
    color: var(--primary-color);
    font-weight: bold;
    margin-right: 10px;
    font-size: 1.2rem;
}

/* 页脚 */
footer {
    padding: 60px 5% 40px;
    text-align: center;
    border-top: 1px solid rgba(255,255,255,0.05);
    color: var(--text-muted);
    background-color: #0b1120;
}

.footer-logo {
    font-size: 1.5rem;
    font-weight: 800;
    color: var(--text-main);
    margin-bottom: 15px;
}

.footer-links {
    margin-top: 20px;
    display: flex;
    justify-content: center;
    gap: 20px;
}

.footer-links a {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.9rem;
}

.footer-links a:hover {
    color: var(--text-main);
}

/* 移动端响应式 */
@media (max-width: 768px) {
    .hero h1 { font-size: 3rem; }
    .hero-buttons { flex-direction: column; width: 100%; }
    .hero-buttons .btn { width: 100%; }
    .nav-links { display: none; }
    .price-card.popular { transform: scale(1); }
    .nav-right { gap: 10px; }
}

/* 阿拉伯语 RTL 排版逻辑 */
html[dir="rtl"] {
    text-align: right;
}
html[dir="rtl"] .nav-right {
    flex-direction: row-reverse;
}
html[dir="rtl"] .feature-card {
    text-align: right;
}
html[dir="rtl"] .price-card ul {
    text-align: right;
}
html[dir="rtl"] .price-card ul li::before {
    margin-right: 0;
    margin-left: 10px;
}