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

:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --text: #1f2937;
    --text-light: #6b7280;
    --bg: #ffffff;
    --bg-alt: #f9fafb;
    --border: #e5e7eb;
}

html {
    scroll-behavior: smooth;
}

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

a {
    color: var(--primary);
    text-decoration: none;
    transition: color 0.2s;
}

a:hover {
    color: var(--primary-dark);
}

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(8px);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
}

.nav {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 64px;
}

.nav-brand a {
    font-size: 24px;
    font-weight: 700;
    color: var(--text);
    letter-spacing: -0.5px;
}

.nav-toggle-input {
    display: none;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    width: 32px;
    height: 32px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}

.nav-toggle span {
    display: block;
    width: 100%;
    height: 2px;
    background: var(--text);
    transition: all 0.3s;
}

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

.nav-menu a {
    color: var(--text-light);
    font-size: 15px;
    font-weight: 500;
}

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

/* Main */
.main {
    padding-top: 64px;
}

section {
    padding: 80px 24px;
}

/* Hero */
.hero {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
    padding: 120px 24px;
    background: linear-gradient(180deg, var(--bg-alt) 0%, var(--bg) 100%);
}

.hero h1 {
    font-size: 64px;
    font-weight: 800;
    letter-spacing: -2px;
    color: var(--text);
    margin-bottom: 8px;
}

.hero .subtitle {
    font-size: 20px;
    color: var(--primary);
    font-weight: 500;
    margin-bottom: 24px;
}

.hero .desc {
    font-size: 18px;
    color: var(--text-light);
    max-width: 600px;
    margin: 0 auto 40px;
    line-height: 1.8;
}

.hero-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
    flex-wrap: wrap;
}

.btn {
    display: inline-block;
    padding: 12px 28px;
    font-size: 15px;
    font-weight: 600;
    border-radius: 8px;
    transition: all 0.2s;
}

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

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

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

.btn-secondary:hover {
    border-color: var(--primary);
    color: var(--primary);
}

/* Features */
.features {
    max-width: 1200px;
    margin: 0 auto;
    background: var(--bg);
}

.features h2,
.structure h2,
.install h2 {
    font-size: 32px;
    font-weight: 700;
    text-align: center;
    margin-bottom: 48px;
    color: var(--text);
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.feature-item {
    padding: 32px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 12px;
    transition: box-shadow 0.2s, transform 0.2s;
}

.feature-item:hover {
    box-shadow: 0 8px 30px rgba(0, 0, 0, 0.08);
    transform: translateY(-2px);
}

.feature-icon {
    font-size: 40px;
    margin-bottom: 16px;
}

.feature-item h3 {
    font-size: 18px;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text);
}

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

/* Structure */
.structure {
    max-width: 900px;
    margin: 0 auto;
    background: var(--bg-alt);
    border-radius: 16px;
    padding: 80px 24px;
}

.code-block {
    background: #1f2937;
    color: #e5e7eb;
    padding: 32px;
    border-radius: 12px;
    overflow-x: auto;
    font-size: 14px;
    line-height: 1.8;
}

.code-block code {
    font-family: "SF Mono", Consolas, "Liberation Mono", Menlo, monospace;
}

/* Install */
.install {
    max-width: 800px;
    margin: 0 auto;
}

.install-steps {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 24px;
    margin-bottom: 48px;
}

.install-steps li {
    display: flex;
    align-items: flex-start;
    gap: 20px;
    padding: 24px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 12px;
}

.step-num {
    flex-shrink: 0;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--primary);
    color: #fff;
    font-size: 18px;
    font-weight: 700;
    border-radius: 50%;
}

.step-content h3 {
    font-size: 17px;
    font-weight: 600;
    margin-bottom: 4px;
    color: var(--text);
}

.step-content p {
    font-size: 15px;
    color: var(--text-light);
}

.step-content code {
    background: var(--bg-alt);
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 14px;
    color: var(--primary);
}

.install-cmd {
    text-align: center;
    padding: 24px;
    background: var(--bg-alt);
    border-radius: 12px;
}

.install-cmd p {
    color: var(--text-light);
    margin-bottom: 8px;
}

.install-cmd code {
    font-size: 15px;
    color: var(--text);
    background: var(--bg);
    padding: 8px 16px;
    border-radius: 6px;
    border: 1px solid var(--border);
}

/* Footer */
.footer {
    background: #1f2937;
    color: #9ca3af;
    padding: 48px 24px;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    text-align: center;
}

.footer-brand {
    font-size: 18px;
    margin-bottom: 16px;
}

.footer-brand strong {
    color: #fff;
}

.footer-links {
    display: flex;
    gap: 24px;
    justify-content: center;
    margin-bottom: 16px;
    flex-wrap: wrap;
}

.footer-links a {
    color: #9ca3af;
}

.footer-links a:hover {
    color: #fff;
}

.footer-license {
    font-size: 14px;
    margin-bottom: 8px;
}

.footer-license a {
    color: #9ca3af;
}

.footer-license a:hover {
    color: #fff;
}

.footer-copyright {
    font-size: 14px;
}

/* Mobile */
@media (max-width: 768px) {
    .nav-toggle {
        display: flex;
    }

    .nav-menu {
        display: none;
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        background: #fff;
        flex-direction: column;
        padding: 16px 24px;
        gap: 16px;
        border-bottom: 1px solid var(--border);
    }

    .nav-toggle-input:checked ~ .nav-menu {
        display: flex;
    }

    .nav-toggle-input:checked ~ .nav-toggle span:nth-child(1) {
        transform: translateY(7px) rotate(45deg);
    }

    .nav-toggle-input:checked ~ .nav-toggle span:nth-child(2) {
        opacity: 0;
    }

    .nav-toggle-input:checked ~ .nav-toggle span:nth-child(3) {
        transform: translateY(-7px) rotate(-45deg);
    }

    .hero {
        padding: 80px 24px;
    }

    .hero h1 {
        font-size: 40px;
    }

    .hero .subtitle {
        font-size: 16px;
    }

    .hero .desc {
        font-size: 16px;
    }

    section {
        padding: 60px 24px;
    }

    .features h2,
    .structure h2,
    .install h2 {
        font-size: 26px;
    }

    .feature-grid {
        grid-template-columns: 1fr;
        gap: 16px;
    }

    .feature-item {
        padding: 24px;
    }

    .structure {
        padding: 60px 24px;
    }

    .code-block {
        padding: 20px;
        font-size: 13px;
    }
}