/* ===== Reset & Base ===== */
*, *::before, *::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #dbeafe;
    --green: #059669;
    --green-light: #d1fae5;
    --red: #dc2626;
    --red-light: #fee2e2;
    --text: #1e293b;
    --text-light: #64748b;
    --bg: #ffffff;
    --bg-gray: #f8fafc;
    --border: #e2e8f0;
    --shadow: 0 4px 24px rgba(0,0,0,0.08);
    --radius: 12px;
    --max-w: 1200px;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--text);
    background: var(--bg);
}

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

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

.container {
    max-width: var(--max-w);
    margin: 0 auto;
    padding: 0 24px;
}

/* ===== Header / Nav ===== */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255,255,255,0.95);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
    height: 64px;
}

.header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    text-decoration: none;
}

.logo-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 36px;
    height: 36px;
    background: var(--primary);
    color: #fff;
    font-size: 18px;
    font-weight: 700;
    border-radius: 8px;
}

.logo-text {
    font-size: 20px;
    font-weight: 700;
    color: var(--text);
}

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

.nav a {
    color: var(--text-light);
    font-weight: 500;
    font-size: 15px;
    position: relative;
    padding: 4px 0;
}
.nav a:hover,
.nav a.active { color: var(--primary); }
.nav a.active::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--primary);
    border-radius: 1px;
}

.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}
.hamburger span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text);
    border-radius: 2px;
    transition: 0.3s;
}

/* ===== Hero ===== */
.hero {
    padding: 120px 0 80px;
    background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 50%, #ede9fe 100%);
    overflow: hidden;
}

.hero .container {
    display: flex;
    align-items: center;
    gap: 60px;
}

.hero-content { flex: 1; }

.hero-content h1 {
    font-size: 48px;
    font-weight: 800;
    line-height: 1.2;
    color: var(--text);
    margin-bottom: 16px;
}

.hero-content p {
    font-size: 18px;
    color: var(--text-light);
    margin-bottom: 32px;
    line-height: 1.8;
}

.hero-content .btn + .btn { margin-left: 12px; }

.hero-image { flex: 1; display: flex; justify-content: center; }

.hero-graphic {
    position: relative;
    width: 320px;
    height: 320px;
}

.circle {
    position: absolute;
    border-radius: 50%;
    opacity: 0.5;
}
.circle-1 {
    width: 280px; height: 280px;
    background: var(--primary);
    top: 20px; left: 20px;
    animation: float 6s ease-in-out infinite;
}
.circle-2 {
    width: 200px; height: 200px;
    background: var(--green);
    top: 60px; left: 60px;
    animation: float 8s ease-in-out infinite reverse;
}
.circle-3 {
    width: 120px; height: 120px;
    background: #f59e0b;
    top: 100px; left: 100px;
    animation: float 5s ease-in-out infinite;
}

.caps-icon {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    font-size: 64px;
    z-index: 1;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0); }
    50% { transform: translate(0, -20px); }
}

/* ===== Buttons ===== */
.btn {
    display: inline-block;
    padding: 12px 28px;
    font-size: 15px;
    font-weight: 600;
    border-radius: 8px;
    border: 2px solid transparent;
    cursor: pointer;
    transition: all 0.2s;
    text-align: center;
    text-decoration: none;
}
.btn-primary {
    background: var(--primary);
    color: #fff !important;
    border-color: var(--primary);
}
.btn-primary:hover {
    background: var(--primary-dark);
    border-color: var(--primary-dark);
}
.btn-outline {
    background: transparent;
    color: var(--primary) !important;
    border-color: var(--primary);
}
.btn-outline:hover {
    background: var(--primary);
    color: #fff !important;
}
.btn-sm {
    padding: 8px 20px;
    font-size: 14px;
}
.btn-lg {
    padding: 16px 40px;
    font-size: 18px;
}

/* ===== Sections ===== */
.section {
    padding: 80px 0;
}

.section-title {
    font-size: 32px;
    font-weight: 700;
    text-align: center;
    margin-bottom: 8px;
    color: var(--text);
}

.section-subtitle {
    font-size: 16px;
    text-align: center;
    color: var(--text-light);
    margin-bottom: 48px;
}

/* ===== Features ===== */
.features-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.feature-card {
    padding: 32px 24px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    text-align: center;
    transition: transform 0.2s, box-shadow 0.2s;
}
.feature-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow);
}
.feature-icon {
    font-size: 36px;
    margin-bottom: 16px;
}
.feature-card h3 {
    font-size: 18px;
    margin-bottom: 8px;
    color: var(--text);
}
.feature-card p {
    font-size: 14px;
    color: var(--text-light);
    line-height: 1.6;
}

/* ===== Projects ===== */
.projects-preview { background: var(--bg-gray); }

.projects-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.project-card {
    position: relative;
    padding: 36px 28px;
    background: var(--bg);
    border-radius: var(--radius);
    border: 1px solid var(--border);
    border-top: 4px solid var(--card-color, var(--primary));
    transition: transform 0.2s, box-shadow 0.2s;
}
.project-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow);
}

.card-badge {
    position: absolute;
    top: 16px;
    right: 16px;
    padding: 4px 12px;
    font-size: 12px;
    font-weight: 600;
    border-radius: 20px;
    color: #fff;
    background: var(--primary);
}

.project-card h3 {
    font-size: 22px;
    font-weight: 700;
    margin-bottom: 8px;
    color: var(--text);
}

.card-desc {
    font-size: 14px;
    color: var(--text-light);
    margin-bottom: 20px;
}

.card-features {
    list-style: none;
    margin-bottom: 24px;
}
.card-features li {
    font-size: 14px;
    color: var(--text);
    padding: 6px 0;
}

/* ===== Audience ===== */
.audience-list {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.audience-item {
    padding: 32px 24px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    text-align: center;
    transition: transform 0.2s;
}
.audience-item:hover { transform: translateY(-4px); }

.audience-num {
    display: inline-block;
    font-size: 24px;
    font-weight: 800;
    color: var(--primary);
    opacity: 0.3;
    margin-bottom: 8px;
}

.audience-item h3 {
    font-size: 18px;
    margin-bottom: 6px;
    color: var(--text);
}

.audience-item p {
    font-size: 14px;
    color: var(--text-light);
}

/* ===== CTA ===== */
.cta {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    text-align: center;
    color: #fff;
    padding: 80px 0;
}
.cta h2 {
    font-size: 36px;
    font-weight: 700;
    margin-bottom: 12px;
}
.cta p {
    font-size: 18px;
    margin-bottom: 32px;
    opacity: 0.9;
}
.cta .btn-primary {
    background: #fff;
    color: var(--primary) !important;
    border-color: #fff;
}
.cta .btn-primary:hover {
    background: transparent;
    color: #fff !important;
}

/* ===== Footer ===== */
.footer {
    background: #1e293b;
    color: #cbd5e1;
    padding: 60px 0 0;
}

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

.footer-brand h3 {
    font-size: 20px;
    font-weight: 700;
    color: #fff;
    margin-bottom: 8px;
}
.footer-brand p { font-size: 14px; }

.footer-links h4,
.footer-contact h4,
.footer-wechat h4 {
    font-size: 14px;
    font-weight: 600;
    color: #fff;
    margin-bottom: 16px;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.footer-links ul,
.footer-contact ul {
    list-style: none;
}
.footer-links li,
.footer-contact li {
    margin-bottom: 8px;
    font-size: 14px;
}
.footer-links a {
    color: #94a3b8;
}
.footer-links a:hover { color: #fff; }

.footer-bottom {
    border-top: 1px solid #334155;
    padding: 20px 0;
    text-align: center;
    font-size: 13px;
    color: #64748b;
}

/* ===== 内页 ===== */
.page-header {
    padding: 120px 0 60px;
    background: linear-gradient(135deg, #eff6ff 0%, #dbeafe 100%);
    text-align: center;
}
.page-header h1 {
    font-size: 36px;
    font-weight: 800;
    margin-bottom: 8px;
}
.page-header p {
    font-size: 16px;
    color: var(--text-light);
}

.page-content { padding: 60px 0; }

/* ===== 项目详情页 ===== */
.project-detail {
    margin-bottom: 60px;
    padding: 40px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    border-left: 4px solid var(--card-color, var(--primary));
}
.project-detail:last-child { margin-bottom: 0; }

.project-detail h2 {
    font-size: 28px;
    font-weight: 700;
    margin-bottom: 16px;
}
.project-detail .lead {
    font-size: 16px;
    color: var(--text-light);
    margin-bottom: 32px;
}

.info-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
    margin-bottom: 32px;
}
.info-item {
    display: flex;
    gap: 12px;
    align-items: flex-start;
}
.info-item .label {
    font-weight: 600;
    color: var(--text);
    min-width: 70px;
}
.info-item .value { color: var(--text-light); }

.pros-cons {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
    margin-bottom: 32px;
}
.pros, .cons {
    padding: 20px;
    border-radius: 8px;
}
.pros { background: var(--green-light); }
.cons { background: var(--red-light); }
.pros h4, .cons h4 {
    font-size: 15px;
    margin-bottom: 12px;
}
.pros ul, .cons ul { list-style: none; }
.pros li, .cons li {
    font-size: 14px;
    padding: 4px 0;
}

/* ===== About / Contact ===== */
.about-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: start;
}

.about-text h2 {
    font-size: 28px;
    font-weight: 700;
    margin-bottom: 16px;
}
.about-text p {
    color: var(--text-light);
    margin-bottom: 16px;
    line-height: 1.8;
}

.contact-form {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 36px;
}
.contact-form h3 {
    font-size: 22px;
    font-weight: 700;
    margin-bottom: 24px;
}

.form-group {
    margin-bottom: 16px;
}
.form-group label {
    display: block;
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 6px;
    color: var(--text);
}
.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 10px 14px;
    font-size: 15px;
    border: 1px solid var(--border);
    border-radius: 8px;
    outline: none;
    transition: border-color 0.2s;
    font-family: inherit;
}
.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(37,99,235,0.12);
}
.form-group textarea {
    resize: vertical;
    min-height: 100px;
}

/* ===== Responsive ===== */
@media (max-width: 968px) {
    .hero .container {
        flex-direction: column;
        text-align: center;
    }
    .hero-content h1 { font-size: 36px; }
    .features-grid,
    .audience-list { grid-template-columns: repeat(2, 1fr); }
    .projects-grid { grid-template-columns: 1fr; }
    .footer-grid { grid-template-columns: 1fr; }
    .about-grid { grid-template-columns: 1fr; }
    .info-grid,
    .pros-cons { grid-template-columns: 1fr; }
}

@media (max-width: 600px) {
    .nav {
        position: fixed;
        top: 64px;
        left: 0;
        right: 0;
        background: #fff;
        border-bottom: 1px solid var(--border);
        padding: 16px 24px;
        display: none;
    }
    .nav.active { display: block; }
    .nav ul { flex-direction: column; gap: 16px; }
    .hamburger { display: flex; }

    .hero-content h1 { font-size: 28px; }
    .hero { padding: 100px 0 60px; }
    .section-title { font-size: 26px; }
    .features-grid,
    .audience-list { grid-template-columns: 1fr; }
    .cta h2 { font-size: 26px; }
}