/* 公共样式 */
:root {
    --primary-color: #0066ff;
    --secondary-color: #00a3ff;
    --cta-color: #0066ff;
    --background-color: #f7faff;
    --text-color: #0f172a;
    --muted-text-color: #475569;
    --border-color: #e2e8f0;

    --hero-fallback: linear-gradient(180deg, #f8fafc 0%, #f1f5f9 50%, #e2e8f0 100%);
    --shadow-brand: 0 12px 40px rgba(0, 102, 255, 0.25);
}

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

html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
    -ms-text-size-adjust: 100%;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--background-color);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

@media (max-width: 768px) {
    body {
        font-size: 14px;
    }
}

a {
    text-decoration: none;
    color: inherit;
    -webkit-tap-highlight-color: rgba(0, 102, 255, 0.1);
    touch-action: manipulation;
}

ul {
    list-style: none;
}

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

@media (max-width: 768px) {
    .container {
        padding: 0 16px;
    }
}

.section {
    padding: 80px 0;
}

.section-title {
    text-align: center;
    margin-bottom: 60px;
}

.section-title h2 {
    font-size: 36px;
    margin-bottom: 15px;
}

.section-title p {
    font-size: 18px;
    color: var(--muted-text-color);
}

/* 按钮 */
.btn {
    display: inline-block;
    padding: 12px 30px;
    border-radius: 999px;
    font-weight: 600;
    transition: all 0.2s ease-in-out;
    cursor: pointer;
    border: none;
    text-align: center;
    -webkit-tap-highlight-color: transparent;
    touch-action: manipulation;
}

@media (max-width: 768px) {
    .btn {
        min-height: 44px;
        padding: 12px 24px;
        font-size: 15px;
    }
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--secondary-color) 100%);
    color: #fff;
    box-shadow: var(--shadow-brand);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 16px 50px rgba(0, 102, 255, 0.28);
}

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

.btn-secondary:hover {
    background-color: var(--primary-color);
    color: #fff;
}

/* 卡片 */
.card {
    background: #fff;
    border-radius: 16px;
    padding: 30px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    transition: all 0.3s ease;
}

.card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 40px rgba(0, 102, 255, 0.2);
}