:root {
    --teal: #00745c;
    --green: #48b179;
    --lime: #b3d660;
    --ink: #16332c;
    --muted: #4d665e;
    --paper: #f4f6ef;
    --card: #ffffff;
    --line: #d5e3d4;
    --header-h: 4.25rem;
    --content: 68rem;
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: calc(var(--header-h) + 0.75rem);
}

body {
    margin: 0;
    color: var(--ink);
    background: var(--paper);
    font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
    line-height: 1.6;
}

img {
    max-width: 100%;
    height: auto;
}

a {
    color: var(--teal);
}

a:hover {
    color: #005744;
}

code {
    font-family: Consolas, "Courier New", monospace;
    font-size: 0.92em;
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 10;
    display: flex;
    align-items: center;
    gap: 1.5rem;
    min-height: var(--header-h);
    padding: 0.6rem 1.5rem;
    background: rgba(244, 246, 239, 0.94);
    border-bottom: 1px solid var(--line);
}

.brand {
    display: flex;
    align-items: center;
    margin-right: auto;
}

.brand img,
.site-footer img {
    display: block;
    height: 2.25rem;
    width: auto;
}

.site-nav {
    display: flex;
    gap: 0.35rem;
}

.site-nav a {
    padding: 0.4rem 0.85rem;
    color: var(--ink);
    text-decoration: none;
    border-radius: 999px;
}

.site-nav a:hover,
.site-nav a.is-active {
    color: var(--teal);
    background: rgba(179, 214, 96, 0.35);
}

.menu-toggle {
    display: none;
    padding: 0.35rem 0.8rem;
    color: var(--teal);
    background: transparent;
    border: 1px solid var(--green);
    border-radius: 999px;
    font: inherit;
    cursor: pointer;
}

.hero,
.band {
    width: min(var(--content), calc(100% - 2.5rem));
    margin: 0 auto;
}

.hero {
    display: grid;
    grid-template-columns: 1.3fr 0.7fr;
    gap: 2.5rem;
    align-items: center;
    padding: 4.5rem 0 3.5rem;
}

.eyebrow {
    margin: 0 0 0.6rem;
    color: var(--teal);
    font-size: 0.85rem;
    letter-spacing: 0.12em;
}

.hero h1,
.section-head h2,
.card-grid h3,
.steps h3,
.stack strong {
    margin: 0;
    line-height: 1.25;
}

.hero h1 {
    /* 窄屏按字折行时避免末字单独成行；宽屏仍保持一行大标题 */
    font-size: clamp(1.35rem, 5vw, 2.6rem);
    font-weight: 600;
    text-wrap: balance;
}

.lead,
.section-head p,
.card-grid p,
.stack p,
.note,
.step-hint,
.site-footer p {
    color: var(--muted);
}

.lead {
    max-width: 36rem;
    margin: 1rem 0 0;
    font-size: 1.08rem;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin-top: 1.6rem;
}

.button {
    display: inline-block;
    padding: 0.55rem 1.1rem;
    text-decoration: none;
    border-radius: 999px;
    border: 1px solid transparent;
}

.button-primary {
    color: #fff;
    background: var(--teal);
}

.button-primary:hover {
    color: #fff;
    background: #005744;
}

.button-ghost {
    color: var(--teal);
    background: transparent;
    border-color: var(--green);
}

.hero-mark {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 16rem;
    background:
        radial-gradient(circle at 50% 45%, rgba(179, 214, 96, 0.45), transparent 58%),
        radial-gradient(circle at 50% 60%, rgba(72, 177, 121, 0.18), transparent 70%);
    border-radius: 1.5rem;
}

.hero-mark img {
    width: 7.5rem;
    height: auto;
}

.band {
    padding: 2.5rem 0 3rem;
}

.band-alt {
    width: 100%;
    max-width: none;
    padding-left: max(1.25rem, calc((100% - var(--content)) / 2));
    padding-right: max(1.25rem, calc((100% - var(--content)) / 2));
    background: #fff;
    border-top: 1px solid var(--line);
    border-bottom: 1px solid var(--line);
}

.section-head {
    display: flex;
    gap: 0.85rem;
    align-items: flex-start;
    margin-bottom: 1.5rem;
}

.section-mark {
    width: 1.75rem;
    height: auto;
    margin-top: 0.15rem;
    flex: none;
}

.section-head h2 {
    font-size: 1.55rem;
}

.section-head p {
    margin: 0.35rem 0 0;
}

.card-grid,
.stack,
.steps {
    list-style: none;
    margin: 0;
    padding: 0;
}

.card-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 0.9rem;
}

.card-grid li,
.stack li,
.steps li {
    background: var(--card);
    border: 1px solid var(--line);
    border-radius: 0.9rem;
}

.card-grid li {
    padding: 1rem 1rem 1.05rem;
    border-top: 3px solid var(--lime);
}

.card-grid h3 {
    font-size: 1.02rem;
}

.card-grid p {
    margin: 0.4rem 0 0;
    font-size: 0.94rem;
}

.stack {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 0.9rem;
}

.stack li {
    padding: 1.1rem 1rem 1.15rem;
    background: var(--paper);
}

.stack-label {
    display: inline-block;
    margin-bottom: 0.45rem;
    padding: 0.1rem 0.5rem;
    color: var(--teal);
    background: rgba(179, 214, 96, 0.4);
    border-radius: 999px;
    font-size: 0.78rem;
}

.stack p,
.note,
.step-hint {
    margin: 0.45rem 0 0;
}

.note {
    margin-top: 1rem;
}

.steps {
    display: grid;
    gap: 0.9rem;
}

.steps li {
    padding: 1rem 1.1rem 1.1rem;
    border-left: 3px solid var(--green);
}

.steps h3 {
    font-size: 1.05rem;
}

.steps pre {
    margin: 0.7rem 0 0;
    padding: 0.75rem 0.9rem;
    overflow-x: auto;
    color: var(--ink);
    background: #eef5ea;
    border-radius: 0.55rem;
}

.steps code {
    font-size: 0.88rem;
}

.site-footer {
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    gap: 1rem 1.5rem;
    padding: 1.4rem 1.5rem 1.8rem;
    border-top: 1px solid var(--line);
}

.site-footer p {
    margin: 0;
}

.site-footer a {
    color: var(--muted);
    text-decoration: none;
}

.site-footer a:hover {
    color: var(--teal);
    text-decoration: underline;
}

.menu-toggle:focus-visible,
.site-nav a:focus-visible,
.button:focus-visible,
.brand:focus-visible {
    outline: 2px solid var(--teal);
    outline-offset: 2px;
}

@media (max-width: 960px) {
    .card-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .hero {
        grid-template-columns: 1fr;
        padding-top: 2.8rem;
    }

    .hero-mark {
        min-height: 12rem;
        order: -1;
    }
}

@media (max-width: 720px) {
    .menu-toggle {
        display: inline-block;
    }

    .site-nav {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        flex-direction: column;
        padding: 0.6rem 1rem 0.9rem;
        background: var(--paper);
        border-bottom: 1px solid var(--line);
    }

    .site-header.is-open .site-nav {
        display: flex;
        box-shadow: 0 10px 18px rgba(22, 51, 44, 0.08);
    }

    .site-nav a {
        padding: 0.65rem 0.85rem;
    }

    .stack,
    .card-grid {
        grid-template-columns: 1fr;
    }
}

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