/* ===== 极栈科技 - 官网样式 ===== */

:root {
    --primary: #1a1a2e;
    --accent: #4a7cff;
    --accent-hover: #3560d4;
    --bg: #ffffff;
    --bg-alt: #f8f9fc;
    --text: #2d3748;
    --text-muted: #718096;
    --border: #e2e8f0;
    --radius: 12px;
    --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 1px 2px rgba(0,0,0,0.06);
    --shadow-lg: 0 10px 25px rgba(0,0,0,0.06);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
    color: var(--text);
    line-height: 1.7;
    background: var(--bg);
}

.container {
    max-width: 960px;
    margin: 0 auto;
    padding: 0 24px;
}

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

header nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 64px;
}

.logo {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--primary);
    text-decoration: none;
}

.nav-links {
    display: flex;
    gap: 28px;
}

.nav-links a {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.2s;
}

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

/* ===== Hero ===== */
.hero {
    padding: 100px 0 80px;
    text-align: center;
    background: linear-gradient(135deg, #f0f4ff 0%, #e8eeff 50%, #f8f9fc 100%);
}

.hero h1 {
    font-size: 2rem;
    font-weight: 800;
    color: var(--primary);
    letter-spacing: 0.02em;
    margin-bottom: 12px;
}

.subtitle {
    font-size: 1rem;
    color: var(--text-muted);
    margin-bottom: 8px;
}

.tagline {
    font-size: 1.15rem;
    color: var(--accent);
    font-weight: 500;
}

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

.section.alt {
    background: var(--bg-alt);
}

.section h2 {
    text-align: center;
    font-size: 1.6rem;
    margin-bottom: 48px;
    color: var(--primary);
}

/* ===== Cards ===== */
.card {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 32px;
    box-shadow: var(--shadow);
}

.info-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
    margin-top: 24px;
    padding-top: 24px;
    border-top: 1px solid var(--border);
}

.info-item {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.info-item .label {
    font-size: 0.8rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.info-item .value {
    font-size: 0.95rem;
    color: var(--text);
}

.grid-3 {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.grid-3 .card {
    text-align: center;
    padding: 28px 20px;
    transition: transform 0.2s, box-shadow 0.2s;
}

.grid-3 .card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.grid-3 .icon {
    font-size: 2rem;
    margin-bottom: 12px;
}

.grid-3 h3 {
    font-size: 1.05rem;
    margin-bottom: 8px;
    color: var(--primary);
}

.grid-3 p {
    font-size: 0.88rem;
    color: var(--text-muted);
    line-height: 1.6;
}

/* ===== Contact ===== */
.contact-card {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.contact-item {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.contact-item .label {
    font-size: 0.8rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.contact-item a {
    color: var(--accent);
    text-decoration: none;
    font-size: 1.05rem;
}

.contact-item a:hover { text-decoration: underline; }

/* ===== Footer ===== */
footer {
    background: var(--primary);
    color: rgba(255,255,255,0.7);
    padding: 40px 0;
    text-align: center;
    font-size: 0.85rem;
    line-height: 2;
}

footer a {
    color: rgba(255,255,255,0.85);
    text-decoration: none;
}

footer a:hover { color: #fff; }

.icp { font-size: 0.8rem; opacity: 0.6; }
.links { margin-top: 8px; }

/* ===== Privacy Page ===== */
.privacy-hero {
    padding: 60px 0 40px;
    background: linear-gradient(135deg, #f0f4ff 0%, #f8f9fc 100%);
}

.privacy-hero h1 { text-align: center; }
.privacy-hero .date { text-align: center; color: var(--text-muted); margin-top: 8px; }

.privacy-content {
    padding: 60px 0;
    max-width: 780px;
    margin: 0 auto;
}

.privacy-content h2 {
    font-size: 1.3rem;
    color: var(--primary);
    margin: 36px 0 12px;
}

.privacy-content h2:first-of-type { margin-top: 0; }

.privacy-content p, .privacy-content li {
    color: var(--text);
    margin-bottom: 8px;
}

.privacy-content ul {
    padding-left: 20px;
    margin-bottom: 16px;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
    .nav-links { gap: 16px; }
    .nav-links a { font-size: 0.8rem; }

    .hero { padding: 60px 0 50px; }
    .hero h1 { font-size: 1.4rem; }

    .section { padding: 50px 0; }
    .section h2 { font-size: 1.35rem; margin-bottom: 32px; }

    .info-grid { grid-template-columns: 1fr; }
    .grid-3 { grid-template-columns: 1fr 1fr; }

    .privacy-content { padding: 0 24px; }
}

@media (max-width: 480px) {
    .grid-3 { grid-template-columns: 1fr; }
    .nav-links { gap: 10px; }
}