:root {
    --bg: #f5f7fb;
    --bg-soft: #eef3fb;
    --surface: #ffffff;
    --surface-2: #f8fbff;
    --text: #111827;
    --text-soft: #5b6475;
    --line: #dfe6f1;
    --primary: #0f172a;
    --accent: #2563eb;
    --accent-soft: #dbeafe;
    --shadow: 0 20px 50px rgba(15, 23, 42, 0.08);
    --radius: 24px;
    --container: 1200px;
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Arial, sans-serif;
    background:
        radial-gradient(circle at top left, rgba(37, 99, 235, 0.08), transparent 28%),
        radial-gradient(circle at right center, rgba(14, 165, 233, 0.06), transparent 26%),
        var(--bg);
    color: var(--text);
    line-height: 1.6;
}

img {
    max-width: 100%;
    display: block;
}

a {
    color: inherit;
    text-decoration: none;
}

.container {
    width: min(100% - 32px, var(--container));
    margin: 0 auto;
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(245, 247, 251, 0.86);
    backdrop-filter: blur(14px);
    border-bottom: 1px solid rgba(223, 230, 241, 0.7);
}

.header-inner {
    min-height: 84px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 14px;
    min-width: 0;
}

.brand-logo {
    width: 52px;
    height: 52px;
    flex: 0 0 52px;
}

.brand-text {
    display: flex;
    flex-direction: column;
    min-width: 0;
}

.brand-title {
    font-size: 20px;
    font-weight: 800;
    letter-spacing: -0.02em;
    line-height: 1.1;
}

.brand-subtitle {
    color: var(--text-soft);
    font-size: 13px;
    line-height: 1.2;
}

.main-nav {
    display: flex;
    align-items: center;
    gap: 24px;
}

.main-nav a {
    color: var(--text-soft);
    font-size: 15px;
    font-weight: 600;
    transition: color 0.2s ease;
}

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

.hero {
    padding: 72px 0 48px;
}

.hero-grid {
    display: grid;
    grid-template-columns: 1.1fr 0.9fr;
    gap: 36px;
    align-items: center;
}

.eyebrow {
    display: inline-flex;
    align-items: center;
    min-height: 34px;
    padding: 0 14px;
    border-radius: 999px;
    background: var(--accent-soft);
    color: var(--accent);
    font-size: 13px;
    font-weight: 700;
    margin-bottom: 18px;
}

.hero h1 {
    margin: 0 0 20px;
    font-size: clamp(36px, 5vw, 64px);
    line-height: 1.02;
    letter-spacing: -0.04em;
}

.hero-text {
    margin: 0 0 24px;
    font-size: 18px;
    color: var(--text-soft);
    max-width: 700px;
}

.hero-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-bottom: 28px;
}

.hero-tags span {
    padding: 10px 14px;
    border-radius: 999px;
    background: rgba(255, 255, 255, 0.9);
    border: 1px solid var(--line);
    color: var(--primary);
    font-size: 14px;
    font-weight: 700;
    box-shadow: 0 10px 24px rgba(15, 23, 42, 0.03);
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 14px;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 52px;
    padding: 0 22px;
    border-radius: 14px;
    font-size: 15px;
    font-weight: 800;
    transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.2s ease;
}

.btn:hover {
    transform: translateY(-1px);
}

.btn-primary {
    background: var(--primary);
    color: #fff;
    box-shadow: 0 18px 40px rgba(15, 23, 42, 0.18);
}

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

.hero-preview {
    position: relative;
}

.preview-card,
.preview-list,
.info-card,
.topic-card,
.format-box {
    background: rgba(255, 255, 255, 0.9);
    border: 1px solid rgba(223, 230, 241, 0.9);
    box-shadow: var(--shadow);
}

.preview-main {
    border-radius: 28px;
    padding: 28px;
    margin-bottom: 18px;
}

.preview-topline {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    margin-bottom: 18px;
}

.preview-badge {
    display: inline-flex;
    align-items: center;
    min-height: 32px;
    padding: 0 12px;
    border-radius: 999px;
    background: var(--primary);
    color: #fff;
    font-size: 13px;
    font-weight: 800;
}

.preview-date {
    color: var(--text-soft);
    font-size: 13px;
    font-weight: 700;
}

.preview-main h2 {
    margin: 0 0 14px;
    font-size: 28px;
    line-height: 1.15;
    letter-spacing: -0.03em;
}

.preview-main p {
    margin: 0;
    color: var(--text-soft);
}

.preview-list {
    border-radius: 24px;
    padding: 14px;
}

.preview-item {
    display: flex;
    gap: 14px;
    padding: 14px;
    border-radius: 18px;
}

.preview-item + .preview-item {
    margin-top: 8px;
}

.preview-item:hover {
    background: var(--surface-2);
}

.preview-dot {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    flex: 0 0 12px;
    margin-top: 9px;
    background: linear-gradient(135deg, var(--accent), #06b6d4);
}

.preview-item strong {
    display: block;
    margin-bottom: 4px;
    font-size: 16px;
}

.preview-item p {
    margin: 0;
    color: var(--text-soft);
    font-size: 14px;
}

.section {
    padding: 48px 0;
}

.section-alt {
    background: linear-gradient(180deg, rgba(255,255,255,0), rgba(255,255,255,0.45));
}

.section-head {
    max-width: 820px;
    margin-bottom: 28px;
}

.section-label {
    display: inline-flex;
    align-items: center;
    min-height: 32px;
    padding: 0 12px;
    border-radius: 999px;
    background: #eaf2ff;
    color: var(--accent);
    font-size: 13px;
    font-weight: 800;
    margin-bottom: 14px;
}

.section-head h2,
.format-content h2 {
    margin: 0 0 14px;
    font-size: clamp(28px, 4vw, 44px);
    line-height: 1.08;
    letter-spacing: -0.03em;
}

.section-head p,
.format-content p {
    margin: 0;
    color: var(--text-soft);
    font-size: 17px;
}

.info-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 18px;
}

.info-card {
    padding: 24px;
    border-radius: var(--radius);
}

.info-card h3 {
    margin: 0 0 10px;
    font-size: 20px;
    line-height: 1.2;
}

.info-card p {
    margin: 0;
    color: var(--text-soft);
}

.topics-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 18px;
}

.topic-card {
    padding: 24px;
    border-radius: var(--radius);
}

.topic-icon {
    width: 48px;
    height: 48px;
    border-radius: 14px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--primary);
    color: #fff;
    font-size: 15px;
    font-weight: 800;
    margin-bottom: 18px;
}

.topic-card h3 {
    margin: 0 0 10px;
    font-size: 20px;
    line-height: 1.2;
}

.topic-card p {
    margin: 0;
    color: var(--text-soft);
}

.format-box {
    border-radius: 32px;
    padding: 32px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
}

.format-points {
    display: grid;
    gap: 14px;
}

.format-point {
    padding: 20px 22px;
    border-radius: 20px;
    background: var(--surface-2);
    border: 1px solid var(--line);
}

.format-point strong {
    display: block;
    margin-bottom: 6px;
    font-size: 17px;
}

.format-point span {
    color: var(--text-soft);
    font-size: 15px;
}

.site-footer {
    padding: 28px 0 40px;
}

.footer-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
    padding-top: 22px;
    border-top: 1px solid var(--line);
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: 14px;
}

.footer-logo {
    width: 44px;
    height: 44px;
    flex: 0 0 44px;
}

.footer-brand strong {
    display: block;
    font-size: 16px;
    margin-bottom: 2px;
}

.footer-brand p,
.footer-copy {
    margin: 0;
    color: var(--text-soft);
    font-size: 14px;
}

@media (max-width: 1100px) {
    .hero-grid,
    .format-box,
    .topics-grid,
    .info-grid {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 780px) {
    .header-inner {
        min-height: auto;
        padding: 16px 0;
        flex-direction: column;
        align-items: flex-start;
    }

    .main-nav {
        flex-wrap: wrap;
        gap: 16px;
    }

    .hero {
        padding-top: 40px;
    }

    .hero-grid,
    .format-box,
    .topics-grid,
    .info-grid,
    .footer-inner {
        grid-template-columns: 1fr;
        flex-direction: column;
        align-items: flex-start;
    }

    .hero h1 {
        font-size: 38px;
    }

    .preview-main h2 {
        font-size: 24px;
    }

    .section,
    .site-footer {
        padding-top: 32px;
        padding-bottom: 32px;
    }

    .format-box {
        padding: 24px;
        border-radius: 24px;
    }
}