@import url("https://fonts.googleapis.com/css2?family=IBM+Plex+Sans:ital,wght@0,400;0,500;0,600;0,700;1,400;1,500;1,600&display=swap");
@import url("https://cdn.jsdelivr.net/gh/orioncactus/pretendard@v1.3.9/dist/web/variable/pretendardvariable-dynamic-subset.min.css");

:root {
    --text: #15161a;
    --muted: #686b75;
    --line: #e9e9ed;
    --surface: #f4f4f5;
    --accent: #245fbc;
    --container: 1152px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    margin: 0;
    color: var(--text);
    background: #fff;
    font-family: "IBM Plex Sans", "Pretendard Variable", Pretendard, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    line-height: 1.6;
    word-break: keep-all;
}
a { color: inherit; text-decoration: none; }
button { color: inherit; font: inherit; }
img { display: block; max-width: 100%; }

.site-header {
    position: sticky;
    z-index: 100;
    top: 0;
    border-bottom: 1px solid rgba(229, 230, 234, .9);
    background: rgba(255, 255, 255, .94);
    backdrop-filter: blur(14px);
}
.header-inner, .footer-inner, .content-container {
    width: min(calc(100% - 40px), var(--container));
    margin: 0 auto;
}
.header-inner {
    height: 76px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.header-spacer { width: 1px; height: 1px; }
.desktop-nav { display: flex; align-items: center; gap: 32px; }
.desktop-nav a, .desktop-nav .nav-upcoming { color: #666a73; font-size: 14px; font-weight: 600; }
.desktop-nav a:hover, .desktop-nav a.active { color: var(--text); }
.nav-upcoming { cursor: default; }
.nav-upcoming::after { content: "SOON"; margin-left: 5px; color: #a1a4ac; font-size: 8px; font-weight: 700; letter-spacing: .07em; vertical-align: top; }
.menu-button { display: none; width: 40px; height: 40px; padding: 0; border: 1px solid var(--line); background: #fff; border-radius: 10px; }
.menu-button span { display: block; width: 17px; height: 1.5px; margin: 3px auto; background: currentColor; }
.mobile-nav { display: none; }

.hero-section {
    min-height: 430px;
    display: flex;
    align-items: center;
    overflow: hidden;
    background-color: #e8f0f6;
    background-image: linear-gradient(90deg, rgba(244, 249, 252, .28), rgba(244, 249, 252, .08)),
                      url("/images/hero-flow-background.png");
    background-position: center;
    background-size: cover;
    background-repeat: no-repeat;
}
.hero-inner {
    width: min(calc(100% - 40px), var(--container));
    margin: 0 auto;
    padding: 70px 0;
    text-align: center;
}
.hero-label { margin: 0 0 15px; color: #3974bf; font-size: 11px; font-weight: 700; letter-spacing: .12em; }
.hero-section h1 { margin: 0; font-size: clamp(42px, 5.5vw, 66px); line-height: 1.12; letter-spacing: -.055em; text-shadow: 0 1px 18px rgba(255, 255, 255, .72); }
.hero-description { max-width: 590px; margin: 26px auto 0; }
.hero-description p { margin: 0; color: #526176; font-size: 16px; line-height: 1.8; }

.blog-section { padding: 0 0 112px; }
.category-tabs {
    min-height: 86px;
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 6px 14px;
}
.category-tab {
    min-height: 36px;
    display: inline-flex;
    align-items: center;
    padding: 6px 14px;
    color: #656873;
    border-radius: 7px;
    font-size: 14px;
    font-weight: 600;
    transition: color .18s ease, background-color .18s ease;
}
.category-tab:hover { color: #17191e; background: #f5f3ef; }
.category-tab.active { color: #17191e; background: var(--surface); font-weight: 700; }

.article-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    column-gap: 28px;
    row-gap: 52px;
    padding-top: 8px;
}
.article-card { min-width: 0; }
.card-thumbnail {
    position: relative;
    display: block;
    overflow: hidden;
    aspect-ratio: 120 / 63;
    background: #eef0f3;
    border-radius: 11px;
}
.card-thumbnail img { width: 100%; height: 100%; object-fit: cover; transition: opacity .2s ease, transform .35s ease; }
.article-card:hover .card-thumbnail img { opacity: .94; transform: scale(1.018); }
.thumbnail-fallback {
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    padding: 28px;
    color: #fff;
    background: linear-gradient(145deg, #1c2b46, #3974b9);
}
.thumbnail-fallback b { align-self: flex-end; font-size: 26px; }
.thumbnail-fallback small { overflow: hidden; color: rgba(255,255,255,.76); font-size: 12px; text-overflow: ellipsis; white-space: nowrap; }
.card-body { padding: 22px 2px 0; }
.card-meta { display: flex; flex-wrap: wrap; align-items: center; gap: 9px; color: #858894; font-size: 13px; }
.card-meta span { color: var(--accent); font-weight: 700; }
.card-meta span::after { content: "·"; margin-left: 9px; color: #b1b3ba; }
.card-body h2 { margin: 13px 0 0; font-size: 22px; font-weight: 600; line-height: 1.38; letter-spacing: -.035em; }
.card-body h2 a { transition: color .18s ease; }
.card-body h2 a:hover { color: var(--accent); }
.empty-state { margin-top: 18px; padding: 90px 20px; border-radius: 12px; color: var(--muted); background: #f7f7f8; text-align: center; }
.empty-state strong { display: block; color: var(--text); font-size: 19px; }
.empty-state p { margin: 7px 0 0; font-size: 14px; }

.site-footer { padding: 52px 0 38px; border-top: 1px solid var(--line); color: var(--muted); }
.footer-inner { display: flex; justify-content: space-between; gap: 40px; }
.footer-inner strong { color: var(--text); font-size: 15px; }
.footer-inner p { margin: 7px 0 0; font-size: 12px; }
.footer-links { display: flex; flex-direction: column; align-items: flex-end; gap: 7px; font-size: 12px; }
.footer-links a:hover { color: var(--accent); }
.github-link { display: grid; width: 34px; height: 34px; place-items: center; color: #3d4149; border: 1px solid var(--line); border-radius: 50%; transition: color .18s ease, border-color .18s ease, background-color .18s ease; }
.github-link:hover { color: #fff !important; border-color: #17191f; background: #17191f; }
.github-link svg { width: 18px; height: 18px; fill: currentColor; }

@media (max-width: 760px) {
    .header-inner, .footer-inner, .content-container, .hero-inner { width: min(calc(100% - 28px), var(--container)); }
    .header-inner { height: 64px; }
    .desktop-nav { display: none; }
    .menu-button { display: block; }
    .mobile-nav { position: absolute; top: 64px; right: 14px; left: 14px; padding: 10px; border: 1px solid var(--line); background: #fff; border-radius: 12px; box-shadow: 0 18px 40px rgba(20,24,30,.12); }
    .mobile-nav.open { display: grid; }
    .mobile-nav a { padding: 11px 12px; font-size: 14px; }
    .mobile-nav .nav-upcoming { display: flex; align-items: center; justify-content: space-between; padding: 11px 12px; color: #8b8e96; font-size: 14px; }
    .mobile-nav .nav-upcoming::after { content: none; }
    .mobile-nav .nav-upcoming small { color: #aaadb4; font-size: 8px; letter-spacing: .08em; }
    .hero-section {
        min-height: 370px;
        background: linear-gradient(135deg, #f8fafc 0%, #f1f5f9 100%);
    }
    .hero-inner { padding: 58px 0; }
    .hero-section h1 { font-size: clamp(40px, 13vw, 54px); }
    .hero-description p { font-size: 14px; line-height: 1.7; }
    .category-tabs { min-height: 78px; gap: 4px; padding: 15px 0; }
    .category-tab { min-height: 34px; padding: 5px 11px; font-size: 13px; }
    .article-grid { grid-template-columns: 1fr; row-gap: 44px; }
    .card-body { padding-top: 18px; }
    .card-body h2 { font-size: 22px; }
    .blog-section { padding-bottom: 80px; }
    .footer-inner { flex-direction: column; }
    .footer-links { align-items: flex-start; }
}

@media (prefers-reduced-motion: reduce) {
    * { scroll-behavior: auto !important; transition-duration: .01ms !important; }
}