/* =========================================================
   智络星海 企业官网 样式
   主题：现代 AI 科技风 · 深色渐变
   ========================================================= */

:root {
    --bg-dark: #060a17;
    --bg-section: #0a1122;
    --bg-card: rgba(255, 255, 255, 0.04);
    --bg-card-hover: rgba(255, 255, 255, 0.07);
    --border-color: rgba(255, 255, 255, 0.1);
    --border-hover: rgba(64, 224, 208, 0.5);
    --text-primary: #f0f6ff;
    --text-secondary: #a7b4cc;
    --text-muted: #6b7a96;
    --grad-1: #27e0d8;
    --grad-2: #6c5ce7;
    --accent: #2fd4d0;
    --radius: 16px;
    --radius-lg: 24px;
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --header-h: 72px;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

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

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

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

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

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ---------- 渐变文字 ---------- */
.grad-text {
    background: linear-gradient(120deg, var(--grad-1), var(--grad-2));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    color: transparent;
}

/* ---------- 导航栏 ---------- */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    height: var(--header-h);
    background: transparent;
    transition: var(--transition);
}

.site-header.scrolled {
    background: rgba(6, 10, 23, 0.85);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid var(--border-color);
}

.header-inner {
    height: var(--header-h);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
}

.brand {
    display: flex;
    align-items: center;
    gap: 12px;
}

.brand-mark {
    width: 40px;
    height: 40px;
    border-radius: 12px;
    background: linear-gradient(135deg, var(--grad-1), var(--grad-2));
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    box-shadow: 0 4px 16px rgba(108, 92, 231, 0.4);
}

.brand-mark svg {
    width: 22px;
    height: 22px;
}

.brand-name {
    font-size: 20px;
    font-weight: 700;
    letter-spacing: 1px;
}

.brand-tag {
    font-size: 10px;
    letter-spacing: 2px;
    color: var(--text-muted);
    border-left: 1px solid var(--border-color);
    padding-left: 12px;
    line-height: 1;
}

.main-nav {
    display: flex;
    align-items: center;
    gap: 28px;
}

.nav-link {
    font-size: 15px;
    color: var(--text-secondary);
    position: relative;
    padding: 6px 2px;
    transition: var(--transition);
}

.nav-link::after {
    content: "";
    position: absolute;
    left: 0;
    bottom: 0;
    width: 0;
    height: 2px;
    border-radius: 2px;
    background: linear-gradient(90deg, var(--grad-1), var(--grad-2));
    transition: var(--transition);
}

.nav-link:hover,
.nav-link.active {
    color: var(--text-primary);
}

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

.nav-cta {
    background: linear-gradient(135deg, var(--grad-1), var(--grad-2));
    color: #fff;
    padding: 10px 22px;
    border-radius: 999px;
    font-weight: 600;
    box-shadow: 0 4px 16px rgba(108, 92, 231, 0.35);
}

.nav-cta::after {
    display: none;
}

.nav-cta:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(108, 92, 231, 0.5);
    color: #fff;
}

.nav-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    z-index: 110;
}

.nav-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--text-primary);
    margin: 5px 0;
    border-radius: 2px;
    transition: var(--transition);
}

.nav-toggle.open span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}

.nav-toggle.open span:nth-child(2) {
    opacity: 0;
}

.nav-toggle.open span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

/* ---------- Hero ---------- */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: calc(var(--header-h) + 48px) 0 80px;
    overflow: hidden;
    background: radial-gradient(ellipse 80% 60% at 70% 20%, rgba(108, 92, 231, 0.18), transparent),
                radial-gradient(ellipse 60% 50% at 20% 80%, rgba(39, 224, 216, 0.12), transparent);
}

.hero-bg {
    position: absolute;
    inset: 0;
    pointer-events: none;
}

.grid-lines {
    position: absolute;
    inset: 0;
    background-image: linear-gradient(rgba(255, 255, 255, 0.04) 1px, transparent 1px),
                      linear-gradient(90deg, rgba(255, 255, 255, 0.04) 1px, transparent 1px);
    background-size: 48px 48px;
    -webkit-mask-image: radial-gradient(ellipse 70% 70% at 50% 40%, #000 30%, transparent 75%);
    mask-image: radial-gradient(ellipse 70% 70% at 50% 40%, #000 30%, transparent 75%);
}

.glow {
    position: absolute;
    border-radius: 50%;
    filter: blur(80px);
    opacity: 0.5;
}

.glow-1 {
    width: 480px;
    height: 480px;
    background: rgba(108, 92, 231, 0.35);
    top: -120px;
    right: -120px;
}

.glow-2 {
    width: 420px;
    height: 420px;
    background: rgba(39, 224, 216, 0.25);
    bottom: -160px;
    left: -100px;
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 880px;
}

.hero-eyebrow {
    display: inline-block;
    font-size: 14px;
    letter-spacing: 3px;
    color: var(--grad-1);
    border: 1px solid rgba(39, 224, 216, 0.3);
    background: rgba(39, 224, 216, 0.08);
    padding: 6px 16px;
    border-radius: 999px;
    margin-bottom: 28px;
}

.hero-title {
    font-size: clamp(40px, 7vw, 76px);
    line-height: 1.15;
    font-weight: 800;
    letter-spacing: 1px;
    margin-bottom: 28px;
}

.hero-sub {
    font-size: clamp(16px, 2vw, 20px);
    color: var(--text-secondary);
    max-width: 640px;
    margin-bottom: 40px;
}

.hero-sub strong {
    color: var(--text-primary);
    font-weight: 600;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    margin-bottom: 64px;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 32px;
    border-radius: 999px;
    font-size: 16px;
    font-weight: 600;
    transition: var(--transition);
    border: 1px solid transparent;
    cursor: pointer;
}

.btn-primary {
    background: linear-gradient(135deg, var(--grad-1), var(--grad-2));
    color: #fff;
    box-shadow: 0 6px 20px rgba(108, 92, 231, 0.4);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: 0 12px 32px rgba(108, 92, 231, 0.55);
}

.btn-ghost {
    background: transparent;
    color: var(--text-primary);
    border-color: var(--border-color);
}

.btn-ghost:hover {
    border-color: var(--accent);
    color: var(--accent);
    transform: translateY(-3px);
}

.hero-stats {
    display: flex;
    gap: 48px;
    flex-wrap: wrap;
}

.stat {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.stat-num {
    font-size: 40px;
    font-weight: 800;
    background: linear-gradient(120deg, var(--grad-1), var(--grad-2));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    color: transparent;
    line-height: 1.2;
}

.stat-label {
    font-size: 14px;
    color: var(--text-muted);
}

/* ---------- Section 通用 ---------- */
.section {
    padding: 96px 0;
}

.section:nth-child(even),
.why,
.process {
    background: var(--bg-section);
}

.section-head {
    text-align: center;
    max-width: 640px;
    margin: 0 auto 64px;
}

.section-eyebrow {
    font-size: 13px;
    letter-spacing: 3px;
    color: var(--accent);
    margin-bottom: 12px;
    text-transform: uppercase;
}

.section-title {
    font-size: clamp(28px, 4vw, 42px);
    font-weight: 800;
    margin-bottom: 16px;
    letter-spacing: 1px;
}

.section-desc {
    color: var(--text-secondary);
    font-size: 16px;
}

/* ---------- 服务卡片 ---------- */
.services-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}

.service-card {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 32px;
    transition: var(--transition);
    position: relative;
    overflow: hidden;
}

.service-card::before {
    content: "";
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, var(--grad-1), var(--grad-2));
    opacity: 0;
    transition: var(--transition);
}

.service-card:hover {
    background: var(--bg-card-hover);
    border-color: var(--border-hover);
    transform: translateY(-6px);
    box-shadow: 0 16px 40px rgba(0, 0, 0, 0.4);
}

.service-card:hover::before {
    opacity: 1;
}

.service-card-wide {
    grid-column: span 1;
}

.service-icon {
    width: 56px;
    height: 56px;
    border-radius: 14px;
    background: linear-gradient(135deg, rgba(39, 224, 216, 0.15), rgba(108, 92, 231, 0.15));
    border: 1px solid var(--border-color);
    color: var(--grad-1);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
    transition: var(--transition);
}

.service-card:hover .service-icon {
    color: #fff;
    background: linear-gradient(135deg, var(--grad-1), var(--grad-2));
    box-shadow: 0 8px 20px rgba(108, 92, 231, 0.4);
}

.service-icon svg {
    width: 26px;
    height: 26px;
}

.service-title {
    font-size: 20px;
    font-weight: 700;
    margin-bottom: 12px;
}

.service-desc {
    color: var(--text-secondary);
    font-size: 15px;
    margin-bottom: 18px;
}

.service-tags {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}

.service-tags li {
    font-size: 12px;
    color: var(--text-secondary);
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    border-radius: 999px;
    padding: 4px 12px;
}

/* ---------- 企业优势 ---------- */
.why-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}

.why-item {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 32px 28px;
    transition: var(--transition);
    position: relative;
}

.why-item:hover {
    transform: translateY(-6px);
    border-color: var(--border-hover);
    background: var(--bg-card-hover);
}

.why-index {
    font-size: 40px;
    font-weight: 800;
    background: linear-gradient(120deg, var(--grad-1), var(--grad-2));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    color: transparent;
    opacity: 0.8;
    display: block;
    margin-bottom: 16px;
}

.why-item h3 {
    font-size: 18px;
    margin-bottom: 10px;
}

.why-item p {
    color: var(--text-secondary);
    font-size: 14px;
}

/* ---------- 服务流程 ---------- */
.process-list {
    list-style: none;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
    counter-reset: step;
}

.process-step {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 32px 28px;
    position: relative;
    transition: var(--transition);
}

.process-step:hover {
    transform: translateY(-6px);
    border-color: var(--border-hover);
    background: var(--bg-card-hover);
}

.step-num {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    border-radius: 12px;
    background: linear-gradient(135deg, var(--grad-1), var(--grad-2));
    color: #fff;
    font-weight: 800;
    font-size: 18px;
    margin-bottom: 20px;
    box-shadow: 0 6px 16px rgba(108, 92, 231, 0.35);
}

.process-step h3 {
    font-size: 18px;
    margin-bottom: 10px;
}

.process-step p {
    color: var(--text-secondary);
    font-size: 14px;
}

/* ---------- 关于我们 ---------- */
.about-inner {
    display: grid;
    grid-template-columns: 1.2fr 0.8fr;
    gap: 64px;
    align-items: center;
}

.about-text p {
    color: var(--text-secondary);
    font-size: 16px;
    margin-bottom: 20px;
}

.about-text p strong {
    color: var(--text-primary);
}

.about-text .section-title {
    text-align: left;
}

.about-stats {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.stat-block {
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius);
    padding: 28px 24px;
    text-align: center;
    transition: var(--transition);
}

.stat-block:hover {
    border-color: var(--border-hover);
    transform: translateY(-4px);
}

.stat-block .stat-num {
    font-size: 34px;
}

.stat-block span:not(.stat-num) {
    font-size: 22px;
    font-weight: 700;
    background: linear-gradient(120deg, var(--grad-1), var(--grad-2));
    -webkit-background-clip: text;
    background-clip: text;
    -webkit-text-fill-color: transparent;
    color: transparent;
}

.stat-block p {
    color: var(--text-muted);
    font-size: 14px;
    margin-top: 6px;
}

/* ---------- 需求收集表单 ---------- */
.inquiry-box {
    max-width: 780px;
    margin: 0 auto;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-lg);
    padding: 40px;
    transition: var(--transition);
}

.inquiry-box:hover {
    border-color: var(--border-hover);
}

.inquiry-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.form-group label {
    font-size: 14px;
    color: var(--text-secondary);
    font-weight: 500;
}

.form-group label em {
    color: var(--grad-1);
    font-style: normal;
    margin-left: 2px;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 12px 16px;
    color: var(--text-primary);
    font: inherit;
    font-size: 15px;
    outline: none;
    transition: var(--transition);
    -webkit-appearance: none;
    appearance: none;
}

.form-group input::placeholder,
.form-group textarea::placeholder {
    color: var(--text-muted);
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    border-color: var(--accent);
    background: rgba(255, 255, 255, 0.07);
    box-shadow: 0 0 0 3px rgba(47, 212, 208, 0.12);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

.form-group select {
    background-image: linear-gradient(45deg, transparent 50%, var(--text-muted) 50%),
                      linear-gradient(135deg, var(--text-muted) 50%, transparent 50%);
    background-position: calc(100% - 20px) calc(50% - 2px),
                         calc(100% - 15px) calc(50% - 2px);
    background-size: 5px 5px, 5px 5px;
    background-repeat: no-repeat;
    cursor: pointer;
}

.form-group select option {
    background: var(--bg-section);
    color: var(--text-primary);
}

.spam-trap {
    position: absolute;
    left: -9999px;
    width: 1px;
    height: 1px;
    opacity: 0;
}

.form-msg {
    font-size: 14px;
    min-height: 22px;
    line-height: 1.5;
}

.form-msg.error {
    color: #ff6b6b;
}

.form-msg.success {
    color: #2dd4a7;
}

.form-submit {
    align-self: flex-start;
    min-width: 168px;
}

.form-submit.loading {
    opacity: 0.7;
    pointer-events: none;
}

/* ---------- 页脚 ---------- */
.site-footer {
    background: #04070f;
    border-top: 1px solid var(--border-color);
}

.footer-inner {
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: 48px;
    padding: 64px 24px;
}

.footer-desc {
    color: var(--text-muted);
    font-size: 14px;
    margin-top: 16px;
    max-width: 360px;
}

.footer-links {
    display: flex;
    gap: 64px;
}

.footer-col h4 {
    font-size: 15px;
    color: var(--text-primary);
    margin-bottom: 16px;
    font-weight: 600;
}

.footer-col ul {
    list-style: none;
}

.footer-col ul li {
    margin-bottom: 10px;
}

.footer-col ul li a {
    color: var(--text-muted);
    font-size: 14px;
    transition: var(--transition);
}

.footer-col ul li a:hover {
    color: var(--accent);
    padding-left: 4px;
}

.footer-bottom {
    border-top: 1px solid var(--border-color);
    padding: 20px 0;
}

.footer-bottom .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 16px;
    flex-wrap: wrap;
}

.footer-bottom p {
    color: var(--text-muted);
    font-size: 13px;
}

.footer-bottom a {
    color: var(--text-muted);
    transition: var(--transition);
}

.footer-bottom a:hover {
    color: var(--accent);
}

/* ---------- 返回顶部 ---------- */
.back-to-top {
    position: fixed;
    right: 28px;
    bottom: 28px;
    width: 46px;
    height: 46px;
    border-radius: 12px;
    border: 1px solid var(--border-color);
    background: rgba(10, 17, 34, 0.9);
    backdrop-filter: blur(8px);
    color: var(--text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transform: translateY(16px);
    transition: var(--transition);
    z-index: 90;
}

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

.back-to-top:hover {
    color: #fff;
    border-color: var(--accent);
}

.back-to-top svg {
    width: 20px;
    height: 20px;
}

/* ---------- 滚动动画 ---------- */
.reveal {
    opacity: 0;
    transform: translateY(28px);
    transition: opacity 0.7s cubic-bezier(0.4, 0, 0.2, 1), transform 0.7s cubic-bezier(0.4, 0, 0.2, 1);
}

.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

/* ---------- 响应式 ---------- */
@media (max-width: 1024px) {
    .services-grid {
        grid-template-columns: repeat(2, 1fr);
    }

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

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

    .about-inner {
        grid-template-columns: 1fr;
        gap: 40px;
    }
}

@media (max-width: 768px) {
    .brand-tag {
        display: none;
    }

    .main-nav {
        position: fixed;
        top: 0;
        right: 0;
        bottom: 0;
        width: min(320px, 80vw);
        background: rgba(6, 10, 23, 0.98);
        flex-direction: column;
        align-items: flex-start;
        justify-content: flex-start;
        gap: 8px;
        padding: calc(var(--header-h) + 20px) 32px 32px;
        transform: translateX(100%);
        transition: var(--transition);
        box-shadow: -16px 0 40px rgba(0, 0, 0, 0.5);
        z-index: 105;
    }

    .main-nav.open {
        transform: translateX(0);
    }

    .nav-link {
        font-size: 18px;
        padding: 12px 0;
        width: 100%;
    }

    .nav-cta {
        margin-top: 12px;
        text-align: center;
    }

    .nav-toggle {
        display: block;
    }

    .section {
        padding: 72px 0;
    }

    .hero {
        min-height: auto;
        padding: calc(var(--header-h) + 48px) 0 64px;
    }

    .hero-stats {
        gap: 32px;
    }

    .footer-inner {
        grid-template-columns: 1fr;
        gap: 32px;
    }

    .footer-links {
        gap: 40px;
    }

    .footer-bottom .container {
        flex-direction: column;
        text-align: center;
    }
}

@media (max-width: 560px) {
    .services-grid,
    .why-grid,
    .process-list {
        grid-template-columns: 1fr;
    }

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

    .inquiry-box {
        padding: 28px 20px;
    }

    .form-submit {
        width: 100%;
    }

    .about-stats {
        grid-template-columns: 1fr 1fr;
    }

    .hero-actions {
        flex-direction: column;
    }

    .hero-actions .btn {
        width: 100%;
    }
}

/* ---------- 减少动画偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    .reveal {
        opacity: 1;
        transform: none;
        transition: none;
    }
}