:root {
    --ink: #172033;
    --ink-soft: #334155;
    --muted: #64748b;
    --line: #e2e8f0;
    --line-strong: #cbd5e1;
    --brand: #315ee7;
    --brand-dark: #2448bd;
    --brand-soft: #eef3ff;
    --surface: #f7f9fc;
    --surface-warm: #fbfaf7;
    --max: 1120px;
    --radius: 18px;
    --shadow: 0 14px 36px rgba(24, 33, 47, .08);
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    color: var(--ink);
    font: 16px/1.75 -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
    background: #fff;
    -webkit-font-smoothing: antialiased;
}

img {
    max-width: 100%;
}

a {
    color: var(--brand);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

a:focus-visible,
button:focus-visible {
    outline: 3px solid rgba(49, 94, 231, .3);
    outline-offset: 3px;
}

.container {
    width: min(calc(100% - 40px), var(--max));
    margin: auto;
}

body > header {
    position: sticky;
    top: 0;
    z-index: 20;
    border-bottom: 1px solid rgba(226, 232, 240, .85);
    background: rgba(255, 255, 255, .92);
    -webkit-backdrop-filter: blur(14px);
    backdrop-filter: blur(14px);
}

.site-nav {
    min-height: 72px;
    display: flex;
    align-items: center;
    gap: 32px;
}

.brand {
    color: var(--ink);
    font-size: 1.25rem;
    font-weight: 850;
    letter-spacing: -.03em;
}

.brand:hover,
.nav-links a:hover {
    text-decoration: none;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 26px;
    margin-left: auto;
}

.nav-links a {
    position: relative;
    color: var(--ink-soft);
    font-size: .94rem;
}

.nav-links a:hover,
.nav-links .active {
    color: var(--brand);
}

.nav-links .active {
    font-weight: 700;
}

.nav-links .active::after {
    position: absolute;
    right: 0;
    bottom: -23px;
    left: 0;
    height: 2px;
    border-radius: 2px;
    background: var(--brand);
    content: "";
}

.nav-toggle {
    display: none;
}

.hero {
    position: relative;
    overflow: hidden;
    padding: 88px 0 82px;
    border-bottom: 1px solid var(--line);
    background:
            radial-gradient(circle at 80% 15%, rgba(49, 94, 231, .13), transparent 30%),
            linear-gradient(145deg, #f7f9ff 0%, #fff 52%, #fbfaf7 100%);
}

.hero::after {
    position: absolute;
    right: -100px;
    bottom: -190px;
    width: 420px;
    height: 420px;
    border: 1px solid rgba(49, 94, 231, .1);
    border-radius: 50%;
    content: "";
}

.hero-grid {
    position: relative;
    z-index: 1;
    display: grid;
    grid-template-columns: minmax(0, 1.7fr) minmax(280px, .85fr);
    gap: 72px;
    align-items: center;
}

.eyebrow {
    margin: 0 0 10px;
    color: var(--brand);
    font-size: .78rem;
    font-weight: 800;
    letter-spacing: .13em;
    text-transform: uppercase;
}

h1,
h2,
h3 {
    letter-spacing: -.025em;
}

h1 {
    max-width: 760px;
    margin: .08em 0 .38em;
    font-size: clamp(2.45rem, 5vw, 4.35rem);
    line-height: 1.13;
}

h2 {
    margin: 0;
    font-size: clamp(1.6rem, 3vw, 2.2rem);
    line-height: 1.3;
}

h3 {
    margin: 12px 0;
    font-size: 1.35rem;
    line-height: 1.45;
}

.lead {
    max-width: 680px;
    margin: 0;
    color: var(--muted);
    font-size: 1.12rem;
    line-height: 1.9;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 22px;
    align-items: center;
    margin-top: 30px;
}

.button {
    display: inline-flex;
    min-height: 46px;
    align-items: center;
    padding: 9px 20px;
    border-radius: 10px;
    color: #fff;
    background: var(--brand);
    box-shadow: 0 8px 20px rgba(49, 94, 231, .2);
    font-weight: 700;
    transition: background .2s ease, box-shadow .2s ease, transform .2s ease;
}

.button:hover {
    color: #fff;
    background: var(--brand-dark);
    box-shadow: 0 10px 24px rgba(49, 94, 231, .25);
    text-decoration: none;
    transform: translateY(-1px);
}

.hero-note {
    padding: 30px;
    border: 1px solid rgba(255, 255, 255, .9);
    border-radius: 22px;
    background: rgba(255, 255, 255, .76);
    box-shadow: var(--shadow);
}

.hero-note-label {
    margin: 0 0 9px;
    color: var(--brand);
    font-size: .78rem;
    font-weight: 800;
    letter-spacing: .1em;
}

.hero-note h2 {
    font-size: 1.35rem;
}

.hero-note > p:not(.hero-note-label) {
    margin: 12px 0 20px;
    color: var(--muted);
}

.topic-chips,
.post-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.topic-chips span {
    padding: 5px 10px;
    border: 1px solid var(--line);
    border-radius: 999px;
    color: var(--ink-soft);
    background: #fff;
    font-size: .78rem;
}

.section {
    padding: 76px 0;
}

.surface {
    background: var(--surface);
}

.section-heading {
    display: flex;
    justify-content: space-between;
    gap: 28px;
    align-items: end;
    margin-bottom: 30px;
}

.section-intro {
    margin: 8px 0 0;
    color: var(--muted);
}

.heading-link,
.text-link {
    font-weight: 700;
}

.heading-link {
    flex: 0 0 auto;
    margin-bottom: 4px;
}

.article-grid {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 26px;
}

.post-card {
    min-width: 0;
    overflow: hidden;
    border: 1px solid var(--line);
    border-radius: var(--radius);
    background: #fff;
    box-shadow: 0 5px 18px rgba(24, 33, 47, .045);
    transition: border-color .22s ease, box-shadow .22s ease, transform .22s ease;
}

.post-card:hover {
    border-color: var(--line-strong);
    box-shadow: var(--shadow);
    transform: translateY(-3px);
}

.post-cover {
    position: relative;
    display: block;
    overflow: hidden;
    aspect-ratio: 16 / 10;
    background: var(--brand-soft);
}

.post-cover img,
.post-cover-placeholder {
    width: 100%;
    height: 100%;
}

.post-cover img {
    display: block;
    object-fit: cover;
    transition: transform .35s ease;
}

.post-card:hover .post-cover img {
    transform: scale(1.025);
}

.post-cover-placeholder {
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    padding: 26px;
    color: #dbe6ff;
    background:
            radial-gradient(circle at 75% 20%, rgba(255, 255, 255, .18), transparent 26%),
            linear-gradient(145deg, #172b55, #315ee7);
    font-size: .85rem;
    font-weight: 700;
    letter-spacing: .08em;
}

.post-cover-placeholder[hidden] {
    display: none;
}

.cover-mark {
    color: rgba(255, 255, 255, .18);
    font-size: clamp(4rem, 10vw, 7rem);
    font-weight: 900;
    line-height: 1;
}

.post-content {
    display: flex;
    min-height: 305px;
    flex-direction: column;
    padding: 25px 26px 23px;
}

.post-meta {
    display: flex;
    justify-content: space-between;
    gap: 16px;
    align-items: center;
    color: var(--muted);
    font-size: .82rem;
}

.post-category {
    padding: 3px 10px;
    border-radius: 999px;
    color: var(--brand-dark);
    background: var(--brand-soft);
    font-weight: 700;
}

.post-category:hover {
    text-decoration: none;
}

.post-card h3 a {
    color: var(--ink);
    overflow-wrap: anywhere;
}

.post-card h3 a:hover {
    color: var(--brand);
    text-decoration: none;
}

.post-summary {
    display: -webkit-box;
    overflow: hidden;
    margin: 0 0 18px;
    color: var(--muted);
    line-height: 1.8;
    -webkit-box-orient: vertical;
    -webkit-line-clamp: 3;
}

.post-tags {
    margin-top: auto;
}

.post-tags a {
    max-width: 150px;
    overflow: hidden;
    color: var(--muted);
    font-size: .78rem;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.post-tags a:hover {
    color: var(--brand);
}

.post-footer {
    display: flex;
    justify-content: space-between;
    gap: 20px;
    align-items: center;
    margin-top: 20px;
    padding-top: 17px;
    border-top: 1px solid var(--line);
    font-size: .9rem;
}

.post-likes {
    color: var(--muted);
}

.category-list {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 14px;
}

.category-list a {
    display: flex;
    min-width: 0;
    justify-content: space-between;
    gap: 14px;
    align-items: center;
    padding: 16px 18px;
    border: 1px solid var(--line);
    border-radius: 12px;
    color: var(--ink);
    background: #fff;
    transition: border-color .2s ease, box-shadow .2s ease, transform .2s ease;
}

.category-list a:hover {
    border-color: var(--line-strong);
    box-shadow: 0 8px 20px rgba(24, 33, 47, .06);
    text-decoration: none;
    transform: translateY(-2px);
}

.category-list strong {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.category-list span {
    flex: 0 0 auto;
    color: var(--muted);
    font-size: .82rem;
}

.about-strip {
    background: var(--surface-warm);
}

.about-strip-inner {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 70px;
    align-items: center;
}

.about-strip-inner p:not(.eyebrow) {
    margin: 0 0 12px;
    color: var(--muted);
}

.prose {
    max-width: 760px;
}

.prose h1 {
    font-size: clamp(2rem, 5vw, 3.5rem);
}

.prose h2 {
    margin-top: 1.5em;
    font-size: 1.5rem;
}

.narrow {
    padding: 0;
}

.empty {
    padding: 30px;
    border: 1px dashed var(--line-strong);
    border-radius: 12px;
    color: var(--muted);
    text-align: center;
}

.site-footer {
    padding: 42px 0 20px;
    color: #d9e1ee;
    background: #141d2e;
}

.footer-grid {
    display: flex;
    justify-content: space-between;
    gap: 36px;
}

.footer-grid p {
    margin: .3rem 0;
    color: #aebbd0;
}

.footer-grid nav {
    display: flex;
    flex-wrap: wrap;
    gap: 8px 18px;
    align-content: start;
}

.site-footer a {
    color: #eef3ff;
}

.copyright {
    margin-top: 28px;
    padding-top: 17px;
    border-top: 1px solid #334158;
    color: #9faec4;
    font-size: .84rem;
}

@media (max-width: 900px) {
    .hero-grid {
        grid-template-columns: minmax(0, 1.4fr) minmax(260px, .8fr);
        gap: 38px;
    }

    .category-list {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }
}

@media (max-width: 720px) {
    .container {
        width: min(calc(100% - 30px), var(--max));
    }

    .site-nav {
        min-height: 64px;
        flex-wrap: wrap;
        gap: 12px;
    }

    .nav-toggle {
        display: block;
        margin-left: auto;
        padding: 6px 11px;
        border: 1px solid var(--line);
        border-radius: 7px;
        color: var(--ink);
        background: #fff;
    }

    .nav-links {
        display: none;
        order: 3;
        width: 100%;
        margin: 0;
        padding: 8px 0 16px;
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }

    .nav-links.open {
        display: flex;
    }

    .nav-links .active::after {
        display: none;
    }

    .hero {
        padding: 58px 0 52px;
    }

    .hero-grid,
    .article-grid,
    .about-strip-inner {
        grid-template-columns: 1fr;
    }

    .hero-grid,
    .about-strip-inner {
        gap: 32px;
    }

    .hero-copy br {
        display: none;
    }

    h1 {
        font-size: clamp(2.2rem, 12vw, 3.25rem);
    }

    .hero-note {
        padding: 24px;
    }

    .section {
        padding: 54px 0;
    }

    .section-heading,
    .footer-grid {
        display: block;
    }

    .heading-link {
        display: inline-block;
        margin-top: 12px;
    }

    .article-grid {
        gap: 20px;
    }

    .post-content {
        min-height: 0;
    }

    .category-list {
        grid-template-columns: 1fr;
    }

    .footer-grid nav {
        margin-top: 20px;
    }
}

@media (max-width: 420px) {
    .hero-actions {
        align-items: flex-start;
        flex-direction: column;
    }

    .post-content {
        padding: 21px 20px 20px;
    }

    .post-meta {
        align-items: flex-start;
        flex-direction: column;
        gap: 8px;
    }
}

@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    *,
    *::before,
    *::after {
        scroll-behavior: auto !important;
        transition-duration: .01ms !important;
    }
}