:root {
    --ink: #17312b;
    --text: #31433d;
    --muted: #687a72;
    --white: #ffffff;
    --mist: #f4f8f5;
    --line: #dce8df;
    --field: #176a43;
    --leaf: #2c8a56;
    --blue: #153f73;
    --gold: #c99232;
    --gold-soft: #fff5df;
    --shadow: 0 12px 30px rgba(23, 49, 43, 0.1);
    --radius: 8px;
    --font: "Noto Sans SC", "Microsoft YaHei", "PingFang SC", Arial, sans-serif;
}

* {
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    margin: 0;
    font-family: var(--font);
    color: var(--text);
    background: var(--mist);
    line-height: 1.7;
}

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

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

.topbar {
    background: #0f2c25;
    color: rgba(255, 255, 255, 0.88);
    font-size: 14px;
}

.topbar-inner,
.header-inner,
.nav-inner,
.section-inner,
.footer-inner,
.page-main {
    max-width: 1280px;
    margin: 0 auto;
    padding-left: 28px;
    padding-right: 28px;
}

.topbar-inner {
    min-height: 38px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 18px;
}

.site-header {
    position: relative;
    color: var(--white);
    background: #143d32;
    overflow: hidden;
}

.site-header::before {
    content: "";
    position: absolute;
    inset: 0;
    background:
        linear-gradient(90deg, rgba(15, 44, 37, 0.95), rgba(15, 44, 37, 0.72), rgba(21, 63, 115, 0.55)),
        url("../assets/south-breeding-hero.png") center / cover no-repeat;
}

.header-inner {
    position: relative;
    min-height: 188px;
    display: flex;
    align-items: center;
    gap: 24px;
}

.brand-mark {
    width: 92px;
    height: 92px;
    padding: 8px;
    border-radius: 50%;
    display: grid;
    place-items: center;
    background: rgba(255, 255, 255, 0.92);
    flex: 0 0 auto;
    box-shadow: 0 10px 24px rgba(0, 0, 0, 0.18);
}

.brand-mark img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.header-copy {
    min-width: 0;
}

.site-kicker {
    margin: 0 0 10px;
    font-size: 17px;
    letter-spacing: 1px;
    color: rgba(255, 255, 255, 0.9);
}

.site-title {
    margin: 0;
    max-width: 980px;
    font-size: clamp(28px, 3.1vw, 44px);
    line-height: 1.28;
    font-weight: 800;
    letter-spacing: 0;
}

.site-subtitle {
    margin: 14px 0 0;
    font-size: 18px;
    color: rgba(255, 255, 255, 0.9);
}

.nav {
    position: sticky;
    top: 0;
    z-index: 20;
    background: linear-gradient(90deg, #12382f, #153f73);
    box-shadow: 0 8px 18px rgba(15, 44, 37, 0.18);
}

.nav-inner {
    min-height: 58px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 2px;
    padding: 0;
    margin: 0;
    list-style: none;
}

.nav-link {
    display: flex;
    align-items: center;
    min-height: 58px;
    padding: 0 15px;
    color: rgba(255, 255, 255, 0.92);
    font-weight: 600;
    font-size: 15px;
    border-bottom: 4px solid transparent;
}

.nav-link:hover,
.nav-link.active {
    color: #fff;
    background: rgba(255, 255, 255, 0.08);
    border-bottom-color: var(--gold);
}

.search {
    display: flex;
    align-items: center;
    gap: 8px;
}

.search input {
    width: 176px;
    height: 34px;
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 999px;
    padding: 0 14px;
    color: #fff;
    background: rgba(255, 255, 255, 0.12);
    outline: none;
}

.search input::placeholder {
    color: rgba(255, 255, 255, 0.7);
}

.hero {
    background: var(--white);
}

.hero-grid {
    max-width: 1280px;
    margin: 0 auto;
    padding: 42px 28px;
    display: grid;
    grid-template-columns: minmax(0, 1.08fr) minmax(320px, 0.92fr);
    gap: 34px;
    align-items: stretch;
}

.hero-panel {
    padding: 34px;
    border-left: 6px solid var(--gold);
    background: linear-gradient(180deg, #ffffff, #f8fbf8);
    box-shadow: var(--shadow);
    border-radius: var(--radius);
}

.hero-panel h2 {
    margin: 0 0 16px;
    color: var(--ink);
    font-size: 28px;
    line-height: 1.35;
    letter-spacing: 0;
}

.hero-panel p {
    margin: 0 0 18px;
    text-align: justify;
}

.tag-row {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 22px;
}

.tag {
    display: inline-flex;
    align-items: center;
    min-height: 32px;
    padding: 0 12px;
    border-radius: 999px;
    border: 1px solid rgba(44, 138, 86, 0.3);
    color: var(--field);
    background: #f1fbf5;
    font-size: 14px;
    font-weight: 700;
}

.hero-image {
    min-height: 370px;
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    background: #dce8df;
}

.hero-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.section {
    padding: 42px 0;
}

.section-heading {
    display: flex;
    align-items: end;
    justify-content: space-between;
    gap: 20px;
    margin-bottom: 20px;
}

.section-heading h2,
.page-title {
    margin: 0;
    color: var(--ink);
    font-size: 26px;
    line-height: 1.35;
    letter-spacing: 0;
}

.section-heading p {
    margin: 0;
    color: var(--muted);
}

.cards {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
}

.card,
.page-card,
.model-panel,
.chat-panel {
    background: var(--white);
    border: 1px solid var(--line);
    border-radius: var(--radius);
    box-shadow: 0 6px 18px rgba(23, 49, 43, 0.06);
}

.card {
    padding: 22px;
}

.card h3 {
    margin: 0 0 10px;
    color: var(--ink);
    font-size: 19px;
}

.card p {
    margin: 0;
    color: var(--muted);
}

.card-link {
    display: block;
    transition: transform 0.2s ease, border-color 0.2s ease;
}

.card-link:hover {
    transform: translateY(-3px);
    border-color: rgba(44, 138, 86, 0.42);
}

.timeline {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 16px;
}

.highlights-grid {
    grid-template-columns: repeat(5, minmax(0, 1fr));
}

.timeline-item {
    padding: 20px;
    background: var(--white);
    border-top: 4px solid var(--leaf);
    border-radius: var(--radius);
    box-shadow: 0 6px 18px rgba(23, 49, 43, 0.06);
    min-height: 160px;
}

.timeline-item strong {
    display: block;
    color: var(--ink);
    margin-bottom: 8px;
}

.page-main {
    padding-top: 34px;
    padding-bottom: 54px;
}

.breadcrumb {
    margin-bottom: 16px;
    color: var(--muted);
    font-size: 14px;
}

.page-layout {
    display: grid;
    grid-template-columns: 280px minmax(0, 1fr);
    gap: 24px;
    align-items: start;
}

.side-menu {
    position: sticky;
    top: 82px;
    padding: 12px;
    background: var(--white);
    border: 1px solid var(--line);
    border-radius: var(--radius);
}

.side-menu h3 {
    margin: 0 0 10px;
    padding: 12px;
    color: #fff;
    background: linear-gradient(90deg, var(--field), var(--blue));
    border-radius: 6px;
    font-size: 17px;
}

.side-menu a {
    display: block;
    padding: 12px;
    border-radius: 6px;
    color: var(--text);
    border-bottom: 1px solid #edf3ef;
}

.side-menu a:hover,
.side-menu a.active {
    background: #eff8f2;
    color: var(--field);
    font-weight: 700;
}

.page-card {
    padding: 26px;
}

.content-list {
    display: grid;
    gap: 12px;
    margin: 20px 0 0;
}

.content-item {
    padding: 16px;
    border: 1px solid var(--line);
    border-radius: 6px;
    background: #fbfdfb;
}

.pdf-placeholder,
.video-placeholder {
    min-height: 520px;
    display: grid;
    place-items: center;
    text-align: center;
    color: var(--muted);
    background:
        linear-gradient(135deg, rgba(44, 138, 86, 0.08), rgba(21, 63, 115, 0.08)),
        #fff;
    border: 1px dashed #b9cbbb;
    border-radius: var(--radius);
}

.pdf-viewer-wrap {
    display: flex;
    justify-content: center;
    padding: 24px;
    background: #eef3ef;
    border-radius: var(--radius);
}

.pdf-page {
    width: min(100%, 940px);
    aspect-ratio: 210 / 297;
    background: #fff;
    border: 1px solid #c9d6cc;
    box-shadow: 0 14px 34px rgba(23, 49, 43, 0.2);
}

.pdf-page iframe {
    display: block;
    width: 100%;
    height: 100%;
    border: 0;
    background: #fff;
}

.pdf-empty {
    width: 100%;
    height: 100%;
    display: grid;
    place-items: center;
    padding: 36px;
    text-align: center;
    color: var(--muted);
}

.document-showcase,
.declaration-showcase {
    display: grid;
    grid-template-columns: minmax(520px, 1fr) 340px;
    gap: 22px;
    align-items: start;
    margin-top: 20px;
}

.summary-panel {
    padding: 20px;
    background: #fbfdfb;
    border: 1px solid var(--line);
    border-radius: var(--radius);
}

.summary-panel h3 {
    margin: 0 0 14px;
    color: var(--ink);
    font-size: 20px;
}

.summary-panel div {
    padding: 12px 0;
    border-top: 1px solid #e7f0ea;
}

.summary-panel div:first-of-type {
    border-top: 0;
}

.summary-panel strong {
    display: block;
    margin-bottom: 5px;
    color: var(--field);
}

.summary-panel span {
    display: block;
    color: var(--text);
    font-size: 14px;
    line-height: 1.75;
}

.model-shell {
    display: grid;
    grid-template-columns: minmax(0, 0.95fr) minmax(380px, 1.05fr);
    gap: 22px;
}

.model-panel,
.chat-panel {
    padding: 22px;
}

.model-panel h2,
.chat-panel h2 {
    margin: 0 0 16px;
    color: var(--ink);
    font-size: 22px;
}

.form-grid {
    display: grid;
    gap: 14px;
}

.field label {
    display: block;
    margin-bottom: 6px;
    color: var(--ink);
    font-weight: 700;
    font-size: 14px;
}

.field input,
.field select,
.field textarea {
    width: 100%;
    border: 1px solid #cddbd1;
    border-radius: 6px;
    padding: 11px 12px;
    font: inherit;
    color: var(--text);
    background: #fff;
}

.field textarea {
    min-height: 118px;
    resize: vertical;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 42px;
    padding: 0 18px;
    border: 0;
    border-radius: 6px;
    color: #fff;
    background: linear-gradient(90deg, var(--field), var(--blue));
    font: inherit;
    font-weight: 800;
    cursor: pointer;
}

.btn.secondary {
    color: var(--field);
    background: #edf7f0;
    border: 1px solid rgba(44, 138, 86, 0.25);
}

.output-box {
    margin-top: 16px;
    padding: 16px;
    min-height: 160px;
    border: 1px solid var(--line);
    border-radius: 6px;
    background: #fbfdfb;
    white-space: pre-wrap;
}

.chat-log {
    height: 430px;
    overflow: auto;
    padding: 14px;
    border: 1px solid var(--line);
    border-radius: 6px;
    background: #f8fbf8;
}

.message {
    max-width: 86%;
    margin-bottom: 12px;
    padding: 12px 14px;
    border-radius: 8px;
    white-space: pre-wrap;
}

.message.user {
    margin-left: auto;
    color: #fff;
    background: var(--blue);
}

.message.bot {
    color: var(--text);
    background: #fff;
    border: 1px solid var(--line);
}

.chat-form {
    display: grid;
    grid-template-columns: minmax(0, 1fr) auto;
    gap: 10px;
    margin-top: 12px;
}

.chat-form input {
    border: 1px solid #cddbd1;
    border-radius: 6px;
    padding: 0 12px;
    font: inherit;
}

.site-footer {
    color: rgba(255, 255, 255, 0.86);
    background: #0f2c25;
}

.footer-inner {
    padding-top: 34px;
    padding-bottom: 26px;
}

.footer-main {
    display: flex;
    justify-content: space-between;
    gap: 28px;
    padding-bottom: 22px;
    border-bottom: 1px solid rgba(255, 255, 255, 0.14);
}

.footer-title {
    margin: 0 0 8px;
    font-size: 22px;
    color: #fff;
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    gap: 20px;
    padding-top: 18px;
    font-size: 13px;
    color: rgba(255, 255, 255, 0.62);
}

@media (max-width: 1060px) {
    .nav-inner,
    .topbar-inner,
    .footer-main,
    .footer-bottom {
        flex-direction: column;
        align-items: flex-start;
    }

    .nav-links {
        flex-wrap: wrap;
    }

    .search {
        width: 100%;
        padding-bottom: 12px;
    }

    .search input {
        width: 100%;
    }

    .hero-grid,
    .model-shell,
    .page-layout,
    .document-showcase,
    .declaration-showcase {
        grid-template-columns: 1fr;
    }

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

    .side-menu {
        position: static;
    }
}

@media (max-width: 760px) {
    .topbar-inner,
    .header-inner,
    .nav-inner,
    .section-inner,
    .footer-inner,
    .page-main,
    .hero-grid {
        padding-left: 18px;
        padding-right: 18px;
    }

    .header-inner {
        min-height: 230px;
        align-items: flex-end;
        padding-bottom: 28px;
    }

    .brand-mark {
        display: none;
    }

    .cards,
    .timeline {
        grid-template-columns: 1fr;
    }

    .hero-panel {
        padding: 24px;
    }

    .chat-form {
        grid-template-columns: 1fr;
    }
}