/* ============================================================
   鲁班 AI 产教联合实验室 - 主样式表
   浅色权威风格
   ============================================================ */

/* ---------- CSS Variables ---------- */
:root {
    --color-bg: #f8f7f4;
    --color-bg-alt: #f0eeea;
    --color-bg-white: #ffffff;
    --color-bg-card: #ffffff;
    --color-bg-card-hover: #faf9f6;
    --color-gold: #b8943e;
    --color-gold-light: #c9a84c;
    --color-gold-dark: #9a7a2e;
    --color-gold-bg: rgba(184, 148, 62, 0.08);
    --color-text: #1a1a1a;
    --color-text-secondary: #4a4a4a;
    --color-text-muted: #777777;
    --color-text-dim: #aaaaaa;
    --color-border: #e5e2db;
    --color-border-light: #eeebe5;
    --color-accent-blue: #3a6fb5;
    --color-accent-teal: #2a9d8f;
    --color-accent-purple: #7c5cbf;

    --font-sans: 'PingFang SC', 'Microsoft YaHei', 'Hiragino Sans GB', 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-serif: 'Noto Serif SC', 'STSong', 'SimSun', 'Songti SC', Georgia, serif;

    --nav-height: 72px;
    --container-max: 1140px;
    --section-py: 88px;
    --radius: 6px;
    --radius-lg: 12px;
    --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 16px rgba(0,0,0,0.08);
    --shadow-lg: 0 8px 32px rgba(0,0,0,0.1);
}

/* ---------- Reset & Base ---------- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html {
    scroll-behavior: smooth;
    scroll-padding-top: var(--nav-height);
}

body {
    font-family: var(--font-sans);
    background-color: var(--color-bg);
    color: var(--color-text);
    line-height: 1.7;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
}

a { color: inherit; text-decoration: none; }
ul { list-style: none; }
img { max-width: 100%; display: block; }

/* ---------- Scrollbar ---------- */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--color-bg); }
::-webkit-scrollbar-thumb { background: #d0cdc5; border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: #b0ada5; }

/* ============================================================
   HEADER
   ============================================================ */
.header {
    position: fixed;
    top: 0; left: 0; right: 0;
    z-index: 1000;
    height: var(--nav-height);
    background: rgba(255, 255, 255, 0.92);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--color-border);
    transition: var(--transition);
}

.header.scrolled {
    box-shadow: var(--shadow-sm);
}

.nav-container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 40px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 17px;
    letter-spacing: 0.5px;
}

.logo-icon {
    font-size: 26px;
    color: var(--color-gold);
}

.logo-text {
    color: var(--color-text);
}

.nav {
    display: flex;
    gap: 36px;
}

.nav-link {
    font-size: 14px;
    color: var(--color-text-muted);
    position: relative;
    padding: 6px 0;
    transition: color var(--transition);
    letter-spacing: 0.5px;
    font-weight: 500;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--color-gold);
    transition: width var(--transition);
}

.nav-link:hover,
.nav-link.active {
    color: var(--color-gold-dark);
}

.nav-link:hover::after,
.nav-link.active::after {
    width: 100%;
}

/* Mobile Menu Toggle */
.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}

.menu-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--color-text);
    transition: var(--transition);
    border-radius: 1px;
}

.menu-toggle.active span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.menu-toggle.active span:nth-child(2) { opacity: 0; }
.menu-toggle.active span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

/* ============================================================
   HERO
   ============================================================ */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    padding: var(--nav-height) 40px 60px;
    background:
        radial-gradient(ellipse 80% 60% at 50% 40%, rgba(184,148,62,0.06) 0%, transparent 60%),
        linear-gradient(180deg, #fcfbf8 0%, var(--color-bg) 100%);
}

.hero-content {
    text-align: center;
    max-width: 760px;
    z-index: 1;
}

.hero-badge {
    display: inline-block;
    padding: 7px 22px;
    border: 1px solid var(--color-gold);
    border-radius: 50px;
    font-size: 13px;
    color: var(--color-gold-dark);
    letter-spacing: 3px;
    margin-bottom: 36px;
    background: var(--color-gold-bg);
}

.hero-title {
    margin-bottom: 28px;
}

.hero-title-line {
    display: block;
    font-family: var(--font-serif);
    font-weight: 700;
}

.hero-title-line:first-child {
    font-size: 26px;
    color: var(--color-gold);
    letter-spacing: 10px;
    margin-bottom: 2px;
    text-transform: uppercase;
}

.hero-title-main {
    font-size: 52px;
    color: var(--color-text);
    letter-spacing: 6px;
}

.hero-subtitle {
    font-size: 16px;
    color: var(--color-text-muted);
    line-height: 2;
    margin-bottom: 44px;
    letter-spacing: 0.5px;
}

.hero-cta {
    display: flex;
    gap: 18px;
    justify-content: center;
}

/* ---------- Buttons ---------- */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 13px 32px;
    border-radius: 50px;
    font-size: 14px;
    font-weight: 600;
    letter-spacing: 0.5px;
    cursor: pointer;
    transition: all var(--transition);
    border: none;
    font-family: var(--font-sans);
}

.btn-primary {
    background: var(--color-gold);
    color: #fff;
}

.btn-primary:hover {
    background: var(--color-gold-dark);
    transform: translateY(-1px);
    box-shadow: 0 4px 16px rgba(184,148,62,0.3);
}

.btn-outline {
    background: transparent;
    color: var(--color-gold-dark);
    border: 1.5px solid var(--color-gold);
}

.btn-outline:hover {
    background: var(--color-gold-bg);
}

.btn-detail {
    background: transparent;
    color: var(--color-gold-dark);
    border: 1.5px solid var(--color-gold);
    padding: 10px 24px;
    font-size: 13px;
    border-radius: 50px;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    cursor: pointer;
    transition: all var(--transition);
    font-family: var(--font-sans);
}

.btn-detail:hover {
    background: var(--color-gold);
    color: #fff;
    border-color: var(--color-gold);
}

.btn-detail::after {
    content: '→';
    transition: transform var(--transition);
}

.btn-detail:hover::after {
    transform: translateX(3px);
}

/* Scroll Indicator */
.scroll-indicator {
    position: absolute;
    bottom: 36px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    color: var(--color-text-dim);
    font-size: 11px;
    letter-spacing: 2px;
    z-index: 1;
    animation: floatDown 2s ease-in-out infinite;
}

.scroll-arrow {
    width: 18px;
    height: 18px;
    border-right: 2px solid var(--color-text-dim);
    border-bottom: 2px solid var(--color-text-dim);
    transform: rotate(45deg);
}

@keyframes floatDown {
    0%, 100% { transform: translateX(-50%) translateY(0); }
    50% { transform: translateX(-50%) translateY(6px); }
}

/* ============================================================
   SECTIONS 通用
   ============================================================ */
.section {
    padding: var(--section-py) 40px;
    position: relative;
}

.section:nth-child(even) {
    background: var(--color-bg-alt);
}

.section-container {
    max-width: var(--container-max);
    margin: 0 auto;
}

.section-header {
    text-align: center;
    margin-bottom: 48px;
}

.section-number {
    display: block;
    font-family: var(--font-serif);
    font-size: 13px;
    color: var(--color-gold);
    letter-spacing: 4px;
    margin-bottom: 12px;
}

.section-title {
    font-family: var(--font-serif);
    font-size: 38px;
    font-weight: 700;
    color: var(--color-text);
    letter-spacing: 3px;
    margin-bottom: 20px;
}

.section-divider {
    width: 56px;
    height: 3px;
    background: var(--color-gold);
    margin: 0 auto;
    border-radius: 2px;
}

.section-intro {
    text-align: center;
    font-size: 15px;
    color: var(--color-text-muted);
    margin-bottom: 48px;
    letter-spacing: 0.5px;
    max-width: 640px;
    margin-left: auto;
    margin-right: auto;
}

/* ============================================================
   共建成员矩阵
   ============================================================ */
.member-block {
    background: var(--color-bg-white);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: 36px 40px;
    margin-bottom: 28px;
    box-shadow: var(--shadow-sm);
    transition: box-shadow var(--transition);
}

.member-block:hover {
    box-shadow: var(--shadow-md);
}

.member-block-header {
    display: flex;
    align-items: center;
    gap: 18px;
    margin-bottom: 28px;
    padding-bottom: 22px;
    border-bottom: 1px solid var(--color-border-light);
}

.member-block-icon {
    color: var(--color-gold);
    flex-shrink: 0;
}

.member-block-header h3 {
    font-size: 22px;
    font-weight: 700;
    color: var(--color-text);
    letter-spacing: 1px;
    margin-bottom: 2px;
}

.member-block-header p {
    font-size: 13px;
    color: var(--color-text-muted);
    letter-spacing: 0.5px;
}

.member-block-header strong {
    color: var(--color-gold-dark);
}

.member-categories-row {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.member-cat-block {
    /*  */
}

.cat-heading {
    font-size: 14px;
    font-weight: 600;
    color: var(--color-gold-dark);
    margin-bottom: 12px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--color-gold-bg);
    letter-spacing: 0.5px;
}

.cat-list-static {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.cat-list-static li {
    font-size: 13px;
    color: var(--color-text-secondary);
    padding: 6px 0;
    border-bottom: 1px solid var(--color-border-light);
    line-height: 1.5;
}

.cat-list-static li:last-child {
    border-bottom: none;
}

/* 教育端 */
.edu-samples {
    margin-bottom: 24px;
}

.edu-samples-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
    margin-top: 12px;
}

.edu-sample-tag {
    display: block;
    padding: 10px 14px;
    background: var(--color-bg-alt);
    border-radius: var(--radius);
    font-size: 13px;
    color: var(--color-text-secondary);
    text-align: center;
    border: 1px solid transparent;
    transition: all var(--transition);
}

.edu-sample-tag:hover {
    border-color: var(--color-gold);
    background: var(--color-gold-bg);
    color: var(--color-gold-dark);
}

.edu-action {
    text-align: center;
    margin-top: 8px;
}

.edu-action .btn span {
    font-size: 16px;
}

/* ============================================================
   五大核心业务板块 - 竖向布局
   ============================================================ */
.business-row {
    display: flex;
    gap: 32px;
    margin-bottom: 28px;
    background: var(--color-bg-white);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: 36px 40px;
    position: relative;
    transition: all var(--transition);
    box-shadow: var(--shadow-sm);
}

.business-row:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--color-gold);
}

.business-row-num {
    font-family: var(--font-serif);
    font-size: 64px;
    font-weight: 700;
    color: var(--color-border);
    line-height: 1;
    flex-shrink: 0;
    width: 70px;
    transition: color var(--transition);
}

.business-row:hover .business-row-num {
    color: rgba(184, 148, 62, 0.15);
}

.business-row-content {
    flex: 1;
}

.business-row-icon {
    font-size: 28px;
    color: var(--color-gold);
    margin-bottom: 10px;
}

.business-row-content h3 {
    font-size: 22px;
    font-weight: 700;
    color: var(--color-text);
    margin-bottom: 8px;
    letter-spacing: 1px;
}

.business-row-desc {
    font-size: 14px;
    color: var(--color-text-muted);
    margin-bottom: 16px;
    line-height: 1.8;
}

.business-row-list {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 8px 24px;
    margin-bottom: 20px;
}

.business-row-list li {
    font-size: 13px;
    color: var(--color-text-secondary);
    padding-left: 16px;
    position: relative;
    line-height: 1.6;
}

.business-row-list li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 9px;
    width: 5px;
    height: 5px;
    border-radius: 50%;
    background: var(--color-gold);
}

/* ============================================================
   联系我们
   ============================================================ */
.contact-content {
    max-width: 760px;
    margin: 0 auto;
}

.contact-intro {
    text-align: center;
    font-size: 15px;
    color: var(--color-text-muted);
    line-height: 1.9;
    margin-bottom: 40px;
}

.contact-cards {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

.contact-card {
    background: var(--color-bg-white);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: 32px 24px;
    text-align: center;
    transition: all var(--transition);
    box-shadow: var(--shadow-sm);
}

.contact-card:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--color-gold);
    transform: translateY(-2px);
}

.contact-card-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 56px;
    height: 56px;
    border-radius: 50%;
    background: var(--color-gold-bg);
    color: var(--color-gold);
    margin-bottom: 16px;
}

.contact-card-info {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.contact-label {
    font-size: 13px;
    color: var(--color-text-muted);
    letter-spacing: 1px;
}

.contact-value {
    font-size: 15px;
    font-weight: 600;
    color: var(--color-text);
    letter-spacing: 0.5px;
}

/* ============================================================
   FOOTER
   ============================================================ */
.footer {
    background: var(--color-bg-white);
    border-top: 1px solid var(--color-border);
    padding: 44px 40px 28px;
}

.footer-container {
    max-width: var(--container-max);
    margin: 0 auto;
}

.footer-top {
    text-align: center;
    margin-bottom: 28px;
    padding-bottom: 28px;
    border-bottom: 1px solid var(--color-border-light);
}

.footer-brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 10px;
}

.footer-brand .logo-icon { font-size: 22px; color: var(--color-gold); }
.footer-brand .logo-text { font-size: 15px; font-weight: 600; color: var(--color-text); }

.footer-tagline {
    font-size: 13px;
    color: var(--color-text-dim);
    letter-spacing: 3px;
}

.footer-bottom { text-align: center; }
.footer-bottom p {
    font-size: 12px;
    color: var(--color-text-dim);
    letter-spacing: 0.5px;
}

/* ============================================================
   MODAL 悬浮窗
   ============================================================ */
.modal-overlay {
    position: fixed;
    inset: 0;
    z-index: 2000;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    -webkit-backdrop-filter: blur(4px);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.25s ease, visibility 0.25s ease;
    padding: 40px 20px;
}

.modal-overlay.open {
    opacity: 1;
    visibility: visible;
}

.modal-dialog {
    background: #fff;
    border-radius: var(--radius-lg);
    width: 100%;
    max-width: 640px;
    max-height: 80vh;
    display: flex;
    flex-direction: column;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.2);
    transform: translateY(20px);
    transition: transform 0.3s ease;
}

.modal-overlay.open .modal-dialog {
    transform: translateY(0);
}

.modal-dialog.modal-lg {
    max-width: 800px;
    max-height: 85vh;
}

.modal-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 24px 32px;
    border-bottom: 1px solid var(--color-border-light);
    flex-shrink: 0;
}

.modal-title {
    font-family: var(--font-serif);
    font-size: 20px;
    font-weight: 700;
    color: var(--color-text);
    letter-spacing: 1px;
}

.modal-close {
    width: 36px;
    height: 36px;
    border: none;
    background: var(--color-bg-alt);
    border-radius: 50%;
    font-size: 20px;
    color: var(--color-text-muted);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition);
    flex-shrink: 0;
}

.modal-close:hover {
    background: #e8e5df;
    color: var(--color-text);
}

.modal-body {
    padding: 28px 32px;
    overflow-y: auto;
    flex: 1;
}

/* 学校悬浮窗 */
.school-category {
    margin-bottom: 28px;
}

.school-category:last-child { margin-bottom: 0; }

.school-category h4 {
    font-size: 15px;
    font-weight: 600;
    color: var(--color-gold-dark);
    margin-bottom: 12px;
    padding-bottom: 8px;
    border-bottom: 2px solid var(--color-gold-bg);
    letter-spacing: 1px;
}

.school-count {
    font-weight: 400;
    color: var(--color-text-muted);
    font-size: 13px;
}

.school-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.school-tag {
    display: inline-block;
    padding: 6px 14px;
    background: var(--color-bg-alt);
    border-radius: 20px;
    font-size: 13px;
    color: var(--color-text-secondary);
    border: 1px solid transparent;
    transition: all var(--transition);
}

.school-tag:hover {
    background: var(--color-gold-bg);
    border-color: var(--color-gold);
    color: var(--color-gold-dark);
}

/* 业务详情悬浮窗 */
.detail-section {
    margin-bottom: 24px;
}

.detail-section:last-child { margin-bottom: 0; }

.detail-section h4 {
    font-size: 15px;
    font-weight: 600;
    color: var(--color-gold-dark);
    margin-bottom: 10px;
    letter-spacing: 0.5px;
}

.detail-section p {
    font-size: 14px;
    color: var(--color-text-secondary);
    line-height: 1.9;
}

.detail-section ul {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.detail-section li {
    font-size: 14px;
    color: var(--color-text-secondary);
    padding-left: 16px;
    position: relative;
    line-height: 1.7;
}

.detail-section li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 10px;
    width: 5px;
    height: 5px;
    border-radius: 50%;
    background: var(--color-gold);
}

/* ============================================================
   BACK TO TOP
   ============================================================ */
.back-to-top {
    position: fixed;
    bottom: 32px;
    right: 32px;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: var(--color-bg-white);
    border: 1px solid var(--color-border);
    color: var(--color-gold);
    font-size: 16px;
    cursor: pointer;
    z-index: 999;
    opacity: 0;
    visibility: hidden;
    transform: translateY(10px);
    transition: all var(--transition);
    box-shadow: var(--shadow-sm);
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.back-to-top:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--color-gold);
    transform: translateY(-2px);
}

/* ============================================================
   BODY SCROLL LOCK (when modal is open)
   ============================================================ */
body.modal-open {
    overflow: hidden;
}

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 1024px) {
    .member-categories-row { grid-template-columns: repeat(2, 1fr); }
    .member-categories-row .member-cat-block:last-child { grid-column: 1 / -1; }
    .edu-samples-grid { grid-template-columns: repeat(3, 1fr); }
    .business-row { flex-direction: column; gap: 16px; }
    .business-row-num { width: auto; font-size: 48px; }
    .business-row-list { grid-template-columns: 1fr 1fr; }
    .contact-cards { grid-template-columns: 1fr; }
}

@media (max-width: 768px) {
    .menu-toggle { display: flex; }
    .nav {
        position: fixed;
        top: var(--nav-height);
        left: 0; right: 0; bottom: 0;
        background: rgba(255, 255, 255, 0.98);
        backdrop-filter: blur(20px);
        flex-direction: column;
        align-items: center;
        justify-content: center;
        gap: 28px;
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition);
    }
    .nav.open { opacity: 1; visibility: visible; }
    .nav-link { font-size: 17px; }

    .hero-title-main { font-size: 36px; letter-spacing: 3px; }
    .hero-title-line:first-child { font-size: 20px; letter-spacing: 6px; }
    .hero-subtitle { font-size: 14px; }
    .section-title { font-size: 28px; }
    .hero-cta { flex-direction: column; align-items: center; }

    .member-block { padding: 28px 20px; }
    .member-categories-row { grid-template-columns: 1fr; }
    .member-categories-row .member-cat-block:last-child { grid-column: auto; }
    .edu-samples-grid { grid-template-columns: repeat(2, 1fr); }

    .business-row { padding: 28px 20px; }
    .business-row-list { grid-template-columns: 1fr; }

    .modal-dialog { max-width: 95vw; }
    .modal-dialog.modal-lg { max-width: 95vw; }
    .modal-header { padding: 18px 20px; }
    .modal-body { padding: 20px; }
}

@media (max-width: 480px) {
    .section { padding: 56px 16px; }
    .nav-container { padding: 0 16px; }
    .hero { padding: var(--nav-height) 16px 60px; }
    .hero-title-main { font-size: 28px; letter-spacing: 2px; }
    .edu-samples-grid { grid-template-columns: repeat(2, 1fr); }
    .business-row-num { font-size: 40px; }
}