body {
    margin: 0;
    font-family: "Microsoft YaHei", Helvetica, Arial, sans-serif;
    font-size: 17px;
    color: #16324f;
    background:
        radial-gradient(circle at top, rgba(16, 78, 140, 0.14), transparent 30%),
        linear-gradient(180deg, #f4f8fc 0%, #eef3f9 100%);
}

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

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

.site-header {
    position: fixed;
    top: 0;
    left: 0;
    z-index: 999;
    width: 100%;
    height: 72px;
    padding: 0;
    background: rgba(16, 78, 140, 0.95);
    backdrop-filter: blur(12px);
    box-shadow: 0 12px 30px rgba(10, 35, 66, 0.18);
    transition: height 0.25s ease, box-shadow 0.25s ease, background-color 0.25s ease;
}

.site-header.is-compact {
    height: 48px;
    box-shadow: 0 8px 20px rgba(10, 35, 66, 0.14);
}

.top-links {
    position: absolute;
    left: 50%;
    bottom: 0.7em;
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 40%;
    transition: bottom 0.25s ease, transform 0.25s ease;
}

.site-header.is-compact .top-links {
    bottom: 50%;
    transform: translateY(50%);
}

.top-links-left {
    margin-left: -45%;
}

.top-links-right {
    margin-left: 5%;
}

.top-links a {
    flex: 0 0 30%;
    color: #f4f8fc;
    font-size: 0.95rem;
    letter-spacing: 0.02em;
    line-height: 1.5em;
    overflow: hidden;
    text-align: center;
    transition: font-size 0.25s ease, line-height 0.25s ease;
}

.site-header.is-compact .top-links a {
    font-size: 0.88rem;
    line-height: 1.2;
}

.top-links a:hover,
.top-links a:focus-visible {
    color: #d8e8ff;
}

.site-logo {
    position: absolute;
    left: 50%;
    top: 4px;
    width: 100px;
    height: 100px;
    padding: 8px;
    box-sizing: border-box;
    margin-left: -58px;
    border-radius: 50%;
    background: #104e8c;
    box-shadow: 0 10px 24px rgba(6, 26, 54, 0.3);
    transition: top 0.25s ease, width 0.25s ease, height 0.25s ease, padding 0.25s ease, margin-left 0.25s ease, box-shadow 0.25s ease;
}

.site-logo img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.site-header.is-compact .site-logo {
    top: 4px;
    width: 40px;
    height: 40px;
    padding: 4px;
    margin-left: -20px;
    box-shadow: 0 2px 8px rgba(6, 26, 54, 0.16);
}

.hero {
    position: relative;
    margin-top: 72px;
    aspect-ratio: 5 / 2;
    overflow: hidden;
    background: #0c3259;
}

.hero img {
    width: 100%;
    height: 100%;
    display: block;
    filter: brightness(1.06) saturate(1.03);
}

.hero-overlay {
    position: absolute;
    inset: 0;
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    gap: 10px;
    padding: clamp(24px, 5vw, 56px);
    background: linear-gradient(180deg, rgba(6, 22, 40, 0.02) 0%, rgba(6, 22, 40, 0.32) 100%);
    color: #ffffff;
}

.hero-kicker {
    margin: 0;
    font-size: 0.92rem;
    letter-spacing: 0.18em;
    text-transform: uppercase;
    opacity: 0.88;
}

.hero h1 {
    margin: 0;
    max-width: 18ch;
    font-size: clamp(1.8rem, 4.5vw, 3.4rem);
    line-height: 1.08;
}

.hero p:last-child {
    margin: 0;
    font-size: clamp(1rem, 2vw, 1.18rem);
}

.page-shell {
    display: grid;
    grid-template-columns: minmax(220px, 280px) minmax(0, 1fr);
    gap: clamp(20px, 3vw, 40px);
    width: min(1200px, calc(100% - 32px));
    margin: clamp(20px, 4vw, 40px) auto 48px;
    align-items: start;
}

.sidebar,
.content-panel {
    background: rgba(255, 255, 255, 0.9);
    border: 1px solid rgba(16, 78, 140, 0.1);
    border-radius: 24px;
    box-shadow: 0 24px 48px rgba(15, 54, 94, 0.08);
}

.sidebar {
    position: sticky;
    top: 102px;
    overflow: hidden;
}

.sidebar-art {
    position: relative;
    background: linear-gradient(180deg, #dceafb 0%, #f4f8fc 100%);
}

.sidebar-art img {
    width: 100%;
    height: 80px;
    object-fit: cover;
}

.sidebar-art-text {
    position: absolute;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0;
    color: #ffffff;
    font-size: 1.6rem;
    font-weight: 700;
    letter-spacing: 0.04em;
    text-shadow: 0 2px 10px rgba(8, 28, 52, 0.45);
    pointer-events: none;
}

.menu-toggle {
    display: none;
    width: calc(100% - 32px);
    margin: 18px 16px 0;
    padding: 12px 14px;
    border: 0;
    border-radius: 12px;
    background: #104e8c;
    color: #ffffff;
    font: inherit;
    text-align: left;
}

.section-nav {
    padding: 16px;
}

.section-nav ul {
    margin: 0;
    padding: 0;
    list-style: none;
}

.section-nav li + li {
    margin-top: 8px;
}

.section-nav a {
    display: block;
    padding: 12px 14px;
    border-radius: 14px;
    color: #1c3f64;
    transition: background-color 0.2s ease, color 0.2s ease, transform 0.2s ease;
}

.section-nav a:hover,
.section-nav a:focus-visible {
    background: #dfeafb;
    transform: translateX(4px);
}

.section-nav a.is-active {
    background: #104e8c;
    color: #ffffff;
}

.header-nav-toggle {
    display: none;
}

.header-nav-links {
    display: none;
}

.content-panel {
    padding: clamp(24px, 4vw, 40px);
}

.content-header {
    padding-bottom: 18px;
    border-bottom: 1px solid rgba(22, 50, 79, 0.12);
}

.content-label {
    margin: 0 0 8px;
    color: #5f7892;
    font-size: 0.92rem;
    letter-spacing: 0.14em;
    text-transform: uppercase;
}

.content-header h2 {
    margin: 0;
    font-size: clamp(1.4rem, 2.4vw, 2.2rem);
    line-height: 1.2;
}

.content-body {
    padding-top: 24px;
    line-height: 1.95;
    text-align: justify;
}

.content-body .bd {
    font-weight: 700;
}

.content-body a {
    color: #104e8c;
}

.content-body a:hover,
.content-body a:focus-visible {
    color: #0b3157;
}

.content-body p,
.content-body ul {
    margin: 0 0 14px;
}

.content-body ul {
    padding-left: 1.25rem;
}

.content-body li {
    margin-bottom: 8px;
}

.previous-workshop-photo {
    margin: 18px 0 20px;
}

.previous-workshop-photo img {
    width: min(100%, 760px);
    margin: 0 auto;
    border-radius: 16px;
    box-shadow: 0 14px 32px rgba(15, 54, 94, 0.16);
}

@media (max-width: 920px) {
    .site-header {
        position: relative;
        height: auto;
        display: flex;
        align-items: center;
        justify-content: space-between;
        padding: 12px 16px;
    }

    .top-links {
        display: none;
    }

    .site-logo {
        position: static;
        width: 52px;
        height: 52px;
        padding: 5px;
        margin-left: 0;
        box-shadow: 0 2px 8px rgba(6, 26, 54, 0.16);
    }

    .header-nav-toggle {
        display: flex;
        align-items: center;
        gap: 6px;
        padding: 8px 14px;
        margin-right: 24px;
        border: 0;
        border-radius: 10px;
        background: rgba(255,255,255,0.15);
        color: #f4f8fc;
        font: inherit;
        font-size: 0.95rem;
        cursor: pointer;
    }

    .header-nav-links {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: rgba(16, 78, 140, 0.98);
        backdrop-filter: blur(12px);
        padding: 12px 16px 16px;
        box-shadow: 0 8px 20px rgba(10, 35, 66, 0.2);
    }

    .header-nav-links.is-open {
        display: flex;
        flex-direction: column;
        gap: 4px;
    }

    .header-nav-links a {
        padding: 10px 12px;
        border-radius: 10px;
        color: #f4f8fc;
        font-size: 0.95rem;
        transition: background-color 0.2s ease;
    }

    .header-nav-links a:hover {
        background: rgba(255,255,255,0.12);
    }

    .hero {
        margin-top: 0;
    }

    .hero img {
        height: 100%;
        max-height: none;
        object-fit: cover;
    }

    .page-shell {
        grid-template-columns: 1fr;
    }

    .sidebar {
        position: static;
    }

    .menu-toggle {
        display: block;
    }

    .section-nav {
        display: none;
        padding-top: 12px;
    }

    .section-nav.is-open {
        display: block;
    }
}

@media (max-width: 640px) {
    body {
        font-size: 16px;
    }

    .site-header {
        padding: 8px 12px;
    }

    .hero-overlay {
        padding: 20px 16px;
    }

    .page-shell {
        width: min(100% - 16px, 1200px);
        gap: 16px;
        margin-top: 16px;
    }

    .sidebar-art img {
        height: 60px;
    }

    .content-panel {
        padding: 20px 16px;
    }

    .content-body {
        text-align: left;
    }
}