:root {
    --primary: #1E88E5;
    --primary-dark: #1565C0;
    --secondary: #FF6B6B;
    --success: #4CAF50;
    --text: #2C3E50;
    --text-light: #7F8C8D;
    --bg: #F8FAFB;
    --card: #FFFFFF;
    --border: #E1E8ED;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "SF Pro", "PingFang SC", "Microsoft YaHei", sans-serif;
    color: var(--text);
    background: var(--bg);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 24px;
}

/* Header */
header {
    background: var(--card);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(10px);
    background: rgba(255, 255, 255, 0.95);
}

nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 0;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 20px;
    font-weight: 700;
    color: var(--primary);
}

.logo-icon {
    width: 36px;
    height: 36px;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 20px;
}

.nav-links {
    display: flex;
    gap: 32px;
    list-style: none;
}

.nav-links a {
    color: var(--text);
    text-decoration: none;
    font-weight: 500;
    font-size: 15px;
    transition: color 0.2s;
}

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

.nav-cta {
    background: var(--primary);
    color: white;
    padding: 10px 20px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    font-size: 14px;
    transition: background 0.2s;
}

.nav-cta:hover { background: var(--primary-dark); }

/* Hero */
.hero {
    padding: 80px 0 60px;
    text-align: center;
    background: linear-gradient(180deg, #E3F2FD 0%, var(--bg) 100%);
}

.hero h1 {
    font-size: 48px;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: 20px;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero p {
    font-size: 20px;
    color: var(--text-light);
    max-width: 600px;
    margin: 0 auto 40px;
}

.hero-stats {
    display: flex;
    justify-content: center;
    gap: 60px;
    margin-top: 50px;
}

.stat {
    text-align: center;
}

.stat-num {
    font-size: 36px;
    font-weight: 800;
    color: var(--primary);
}

.stat-label {
    font-size: 14px;
    color: var(--text-light);
    margin-top: 4px;
}

/* Features */
.features {
    padding: 80px 0;
}

.section-title {
    text-align: center;
    font-size: 36px;
    font-weight: 800;
    margin-bottom: 12px;
}

.section-subtitle {
    text-align: center;
    color: var(--text-light);
    font-size: 18px;
    margin-bottom: 60px;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
}

.feature-card {
    background: var(--card);
    padding: 32px 28px;
    border-radius: 16px;
    box-shadow: 0 2px 12px rgba(0,0,0,0.04);
    border: 1px solid var(--border);
    transition: all 0.3s;
}

.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(0,0,0,0.08);
}

.feature-icon {
    width: 56px;
    height: 56px;
    background: linear-gradient(135deg, #E3F2FD, #BBDEFB);
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 28px;
    margin-bottom: 20px;
}

.feature-card h3 {
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 12px;
}

.feature-card p {
    color: var(--text-light);
    font-size: 15px;
    line-height: 1.7;
}

/* Screenshots */
.screenshots {
    padding: 80px 0;
    background: var(--card);
}

.screenshot-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 24px;
    margin-top: 40px;
}

.screenshot-item {
    aspect-ratio: 9/16;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    border-radius: 24px;
    box-shadow: 0 8px 24px rgba(30, 136, 229, 0.2);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 14px;
    padding: 20px;
    text-align: center;
}

/* CTA */
.cta {
    padding: 80px 0;
    text-align: center;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
}

.cta h2 {
    font-size: 36px;
    font-weight: 800;
    margin-bottom: 16px;
}

.cta p {
    font-size: 18px;
    margin-bottom: 32px;
    opacity: 0.9;
}

.cta-button {
    display: inline-block;
    background: white;
    color: var(--primary);
    padding: 16px 40px;
    border-radius: 12px;
    text-decoration: none;
    font-weight: 700;
    font-size: 16px;
    transition: transform 0.2s;
}

.cta-button:hover {
    transform: translateY(-2px);
}

/* Footer */
footer {
    background: #1A2332;
    color: #B0BEC5;
    padding: 60px 0 30px;
}

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

.footer-col h4 {
    color: white;
    font-size: 16px;
    font-weight: 700;
    margin-bottom: 16px;
}

.footer-col a {
    display: block;
    color: #B0BEC5;
    text-decoration: none;
    font-size: 14px;
    margin-bottom: 10px;
    transition: color 0.2s;
}

.footer-col a:hover { color: white; }

.footer-bottom {
    border-top: 1px solid #2C3E50;
    padding-top: 30px;
    text-align: center;
    font-size: 13px;
    color: #7F8C8D;
}

/* Article page */
.article {
    max-width: 800px;
    margin: 0 auto;
    padding: 60px 24px;
}

.article h1 {
    font-size: 36px;
    font-weight: 800;
    margin-bottom: 16px;
}

.article-meta {
    color: var(--text-light);
    font-size: 14px;
    margin-bottom: 40px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--border);
}

.article h2 {
    font-size: 24px;
    font-weight: 700;
    margin: 40px 0 16px;
    color: var(--primary);
}

.article h3 {
    font-size: 18px;
    font-weight: 600;
    margin: 24px 0 12px;
}

.article p {
    margin-bottom: 16px;
    line-height: 1.8;
    color: #455A64;
}

.article ul, .article ol {
    margin: 0 0 20px 24px;
    color: #455A64;
}

.article li {
    margin-bottom: 8px;
    line-height: 1.8;
}

.article table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
}

.article th, .article td {
    border: 1px solid var(--border);
    padding: 12px;
    text-align: left;
    font-size: 14px;
}

.article th {
    background: #F8FAFB;
    font-weight: 700;
}

/* Support form */
.support-form {
    max-width: 600px;
    margin: 40px auto;
    background: var(--card);
    padding: 40px;
    border-radius: 16px;
    box-shadow: 0 2px 12px rgba(0,0,0,0.04);
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 600;
    font-size: 14px;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-size: 15px;
    font-family: inherit;
    transition: border-color 0.2s;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary);
}

.form-group textarea {
    min-height: 120px;
    resize: vertical;
}

.btn {
    background: var(--primary);
    color: white;
    border: none;
    padding: 14px 32px;
    border-radius: 8px;
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s;
    width: 100%;
}

.btn:hover { background: var(--primary-dark); }

.btn:disabled {
    background: #B0BEC5;
    cursor: not-allowed;
}

.toast {
    position: fixed;
    top: 24px;
    right: 24px;
    background: var(--success);
    color: white;
    padding: 16px 24px;
    border-radius: 8px;
    font-weight: 600;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    opacity: 0;
    transform: translateY(-20px);
    transition: all 0.3s;
    z-index: 1000;
}

.toast.show {
    opacity: 1;
    transform: translateY(0);
}

/* Responsive */
@media (max-width: 768px) {
    .hero h1 { font-size: 32px; }
    .hero p { font-size: 16px; }
    .hero-stats { gap: 30px; }
    .stat-num { font-size: 28px; }
    .nav-links { display: none; }
    .section-title { font-size: 28px; }
    .footer-grid { grid-template-columns: 1fr 1fr; }
    .article h1 { font-size: 28px; }
}