/* ============================================================
   杭州云许科技有限公司 - 官方网站样式
   Hangzhou Yunxu Technology Co., Ltd. - Official Website
   Design: Modern Professional Corporate Style
   ============================================================ */

/* --- CSS Variables --- */
:root {
    --color-primary: #1a56db;
    --color-primary-dark: #1347b0;
    --color-primary-light: #4f8cf7;
    --color-primary-bg: #ebf2ff;
    --color-accent: #06b6d4;
    --color-accent-dark: #0891b2;
    --color-dark: #0f172a;
    --color-dark-2: #1e293b;
    --color-dark-3: #334155;
    --color-gray: #64748b;
    --color-gray-light: #94a3b8;
    --color-gray-bg: #f1f5f9;
    --color-gray-border: #e2e8f0;
    --color-white: #ffffff;
    --color-success: #10b981;
    --color-warning: #f59e0b;
    --gradient-primary: linear-gradient(135deg, #1a56db 0%, #4f8cf7 50%, #06b6d4 100%);
    --gradient-dark: linear-gradient(135deg, #0f172a 0%, #1e293b 100%);
    --gradient-hero: linear-gradient(160deg, #0f172a 0%, #1a365d 40%, #1e3a5f 70%, #0f172a 100%);
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.08), 0 2px 4px -2px rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 10px 25px -5px rgba(0, 0, 0, 0.1), 0 4px 10px -6px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 50px -12px rgba(0, 0, 0, 0.15);
    --shadow-primary: 0 8px 25px rgba(26, 86, 219, 0.25);
    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --font-cn: -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
    --font-en: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --container: 1200px;
}

/* --- Reset & Base --- */
*, *::before, *::after { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 80px; }
body {
    font-family: var(--font-cn);
    font-size: 16px;
    line-height: 1.7;
    color: var(--color-dark-2);
    background: var(--color-white);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
}
a { text-decoration: none; color: inherit; transition: var(--transition); }
ul { list-style: none; }
img { max-width: 100%; height: auto; display: block; }
.container { max-width: var(--container); margin: 0 auto; padding: 0 24px; }

/* --- Typography --- */
h1, h2, h3, h4, h5, h6 { font-weight: 700; line-height: 1.3; color: var(--color-dark); }

/* --- Buttons --- */
.btn {
    display: inline-flex; align-items: center; gap: 8px;
    padding: 14px 32px; font-size: 15px; font-weight: 600;
    border-radius: var(--radius-md); cursor: pointer;
    transition: all var(--transition); border: 2px solid transparent;
    white-space: nowrap; letter-spacing: 0.01em;
    position: relative; overflow: hidden;
}

/* Hero Primary Button — 探索服务 */
.btn-hero-primary {
    position: relative; overflow: hidden;
    padding: 16px 40px; font-size: 16px; font-weight: 700;
    color: #fff; background: var(--gradient-primary);
    border: none; border-radius: 60px;
    cursor: pointer; letter-spacing: 0.04em;
    box-shadow: 0 8px 32px rgba(26, 86, 219, 0.35), 0 0 0 0 rgba(26, 86, 219, 0.5);
    transition: all 0.4s cubic-bezier(0.25, 0.8, 0.25, 1.2);
    animation: btnPulse 2.5s ease-in-out infinite;
    display: inline-flex; align-items: center; gap: 10px;
    text-decoration: none;
}
.btn-hero-primary::after {
    content: '';
    position: absolute; inset: 2px;
    border-radius: 58px;
    background: transparent;
    box-shadow: inset 0 1px 0 rgba(255,255,255,0.25);
    pointer-events: none;
}
.btn-hero-primary .btn-shimmer {
    position: absolute; top: 0; left: -100%;
    width: 60%; height: 100%;
    background: linear-gradient(90deg,
        transparent 0%,
        rgba(255,255,255,0.15) 40%,
        rgba(255,255,255,0.3) 50%,
        rgba(255,255,255,0.15) 60%,
        transparent 100%
    );
    animation: shimmer 3s ease-in-out infinite;
    pointer-events: none; z-index: 2;
}
.btn-hero-primary .btn-glow {
    position: absolute; inset: -4px;
    border-radius: 64px; opacity: 0;
    background: var(--gradient-primary);
    filter: blur(20px); z-index: -1;
    transition: opacity 0.4s ease;
}
.btn-hero-primary:hover {
    transform: translateY(-3px) scale(1.03);
    box-shadow: 0 16px 48px rgba(26, 86, 219, 0.45), 0 0 0 8px rgba(26, 86, 219, 0.08);
    animation: none;
}
.btn-hero-primary:hover .btn-glow {
    opacity: 0.6;
}
.btn-hero-primary:hover .btn-shimmer {
    animation-duration: 1.5s;
}
.btn-hero-primary:hover .btn-icon {
    transform: translateX(4px);
}
.btn-hero-primary .btn-text {
    position: relative; z-index: 3;
}
.btn-hero-primary .btn-icon {
    position: relative; z-index: 3;
    display: inline-flex; align-items: center;
    transition: transform 0.35s cubic-bezier(0.25, 0.8, 0.25, 1.2);
}
@keyframes btnPulse {
    0%, 100% { box-shadow: 0 8px 32px rgba(26, 86, 219, 0.35), 0 0 0 0 rgba(26, 86, 219, 0.4); }
    50% { box-shadow: 0 8px 32px rgba(26, 86, 219, 0.35), 0 0 0 12px rgba(26, 86, 219, 0); }
}
@keyframes shimmer {
    0% { left: -100%; }
    50%, 100% { left: 120%; }
}

/* Standard Primary Button */
.btn-primary {
    background: var(--gradient-primary); color: var(--color-white);
    box-shadow: var(--shadow-primary);
}
.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 12px 30px rgba(26, 86, 219, 0.35);
}

/* Outline Button */
.btn-outline {
    background: transparent; color: var(--color-white);
    border-color: rgba(255, 255, 255, 0.35);
    padding: 15px 36px; font-size: 16px; font-weight: 600;
    border-radius: 60px; letter-spacing: 0.03em;
    backdrop-filter: blur(4px);
    transition: all 0.35s cubic-bezier(0.25, 0.8, 0.25, 1.1);
}
.btn-outline .btn-text {
    position: relative; z-index: 1;
}
.btn-outline:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: rgba(255, 255, 255, 0.7);
    transform: translateY(-3px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.15);
}
.btn-block { width: 100%; justify-content: center; }

/* ==================== HEADER ==================== */
.header {
    position: fixed; top: 0; left: 0; right: 0; z-index: 1000;
    background: rgba(15, 23, 42, 0.92); backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid rgba(255, 255, 255, 0.06);
    transition: all var(--transition);
}
.header.scrolled {
    background: rgba(15, 23, 42, 0.97);
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.2);
}
.header-inner {
    display: flex; align-items: center; justify-content: space-between;
    height: 72px;
}

/* Logo */
.logo { display: flex; align-items: center; gap: 10px; }
.logo-icon { flex-shrink: 0; }
.logo-text { display: flex; flex-direction: column; }
.logo-cn { font-size: 20px; font-weight: 700; color: var(--color-white); line-height: 1.2; }
.logo-en {
    font-size: 10px; font-weight: 500; color: var(--color-gray-light);
    letter-spacing: 0.12em; text-transform: uppercase; font-family: var(--font-en);
}

/* Nav */
.nav { display: flex; align-items: center; gap: 4px; }
.nav-link {
    padding: 8px 18px; font-size: 14px; font-weight: 500;
    color: var(--color-gray-light); border-radius: var(--radius-sm);
    transition: all var(--transition); position: relative;
}
.nav-link:hover, .nav-link.active { color: var(--color-white); background: rgba(255,255,255,0.08); }
.nav-toggle { display: none; flex-direction: column; gap: 5px; background: none; border: none; cursor: pointer; padding: 8px; }
.nav-toggle span { width: 24px; height: 2px; background: var(--color-white); border-radius: 2px; transition: var(--transition); }

/* ==================== HERO ==================== */
.hero {
    position: relative; min-height: 100vh; display: flex; align-items: center;
    background: var(--gradient-hero); overflow: hidden;
}
.hero-bg { position: absolute; inset: 0; }
.hero-particles { position: absolute; inset: 0; opacity: 0.3; }
.hero::after {
    content: '';
    position: absolute; bottom: 0; left: 0; right: 0; height: 240px;
    background: linear-gradient(to top, var(--color-white) 0%, transparent 100%);
    pointer-events: none;
}
.hero-content {
    position: relative; z-index: 2; text-align: center;
    padding: 120px 24px 80px;
}
.hero-badge {
    display: inline-block; padding: 6px 20px;
    background: rgba(26, 86, 219, 0.2); border: 1px solid rgba(79, 140, 247, 0.3);
    border-radius: 50px; margin-bottom: 28px;
    font-size: 13px; font-weight: 500; color: var(--color-primary-light);
    letter-spacing: 0.06em;
}
.hero-title { margin-bottom: 24px; }
.hero-title-line {
    display: block; font-size: clamp(36px, 6vw, 60px); font-weight: 800;
    color: var(--color-white); letter-spacing: 0.04em;
    background: linear-gradient(135deg, #fff 0%, #c3d9ff 100%);
    -webkit-background-clip: text; -webkit-text-fill-color: transparent;
    background-clip: text;
}
.hero-title-sub {
    display: block; font-size: clamp(14px, 2.5vw, 18px); font-weight: 400;
    color: var(--color-primary-light); letter-spacing: 0.12em;
    font-family: var(--font-en); text-transform: uppercase; margin-top: 8px;
}
.hero-desc {
    font-size: clamp(15px, 2vw, 18px); color: var(--color-gray-light);
    max-width: 640px; margin: 0 auto 36px; line-height: 1.8;
}
.hero-actions {
    display: flex; gap: 16px; justify-content: center; flex-wrap: wrap;
    margin-bottom: 56px;
}
.hero-stats {
    display: flex; justify-content: center; gap: clamp(24px, 5vw, 60px);
    flex-wrap: wrap;
}
.hero-stat-item { text-align: center; }
.hero-stat-num {
    display: block; font-size: clamp(28px, 4vw, 40px); font-weight: 800;
    color: var(--color-white); line-height: 1;
    font-family: var(--font-en);
}
.hero-stat-label {
    display: block; font-size: 13px; color: var(--color-gray-light);
    margin-top: 6px; font-weight: 500;
}
.hero-scroll {
    position: absolute; bottom: 60px; left: 50%; transform: translateX(-50%);
    z-index: 2; display: flex; flex-direction: column; align-items: center; gap: 4px;
    font-size: 12px; color: var(--color-gray-light); animation: bounce 2s ease infinite;
}
@keyframes bounce {
    0%, 100% { transform: translateX(-50%) translateY(0); }
    50% { transform: translateX(-50%) translateY(8px); }
}

/* ==================== SECTIONS ==================== */
.section { padding: 100px 0; }
.section-header { text-align: center; margin-bottom: 60px; }
.section-tag {
    display: inline-block; padding: 4px 16px;
    background: var(--color-primary-bg); color: var(--color-primary);
    border-radius: 50px; font-size: 12px; font-weight: 600;
    letter-spacing: 0.1em; text-transform: uppercase; margin-bottom: 16px;
    font-family: var(--font-en);
}
.section-title { font-size: clamp(28px, 4vw, 40px); font-weight: 800; margin-bottom: 12px; }
.section-title span { color: var(--color-primary); }
.section-subtitle { font-size: 16px; color: var(--color-gray); max-width: 500px; margin: 0 auto; }

/* ==================== ABOUT ==================== */
.about { background: var(--color-white); }
.about-grid {
    display: grid; grid-template-columns: 1fr 1fr; gap: 60px; align-items: center;
}
.about-img-wrapper {
    position: relative; border-radius: var(--radius-lg); overflow: hidden;
}
.about-img-placeholder {
    width: 100%; aspect-ratio: 4/3;
    background: linear-gradient(135deg, #e8f0fe 0%, #d4e4fc 100%);
    border-radius: var(--radius-lg);
    display: flex; align-items: center; justify-content: center;
    color: var(--color-primary);
}
.about-experience {
    position: absolute; bottom: 24px; right: 24px;
    background: var(--color-white); border-radius: var(--radius-md);
    padding: 16px 24px; text-align: center;
    box-shadow: var(--shadow-lg);
}
.exp-year {
    display: block; font-size: 32px; font-weight: 800;
    color: var(--color-primary); font-family: var(--font-en); line-height: 1;
}
.exp-label { font-size: 12px; color: var(--color-gray); margin-top: 4px; }
.about-text h3 { font-size: 26px; margin-bottom: 16px; }
.about-lead { font-size: 17px; color: var(--color-dark-3); margin-bottom: 16px; line-height: 1.8; }
.about-text p { color: var(--color-gray); margin-bottom: 12px; line-height: 1.8; }
.about-features { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-top: 20px; }
.about-feat-item {
    display: flex; align-items: center; gap: 10px;
    font-size: 14px; color: var(--color-dark-3); font-weight: 500;
}

/* ==================== SERVICES ==================== */
.services { background: var(--color-gray-bg); }
.services-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 24px;
}
.service-card {
    background: var(--color-white); border-radius: var(--radius-lg);
    padding: 36px 28px; text-align: center;
    box-shadow: var(--shadow-sm); border: 1px solid var(--color-gray-border);
    transition: all var(--transition); position: relative; overflow: hidden;
}
.service-card::before {
    content: ''; position: absolute; top: 0; left: 0; right: 0; height: 3px;
    background: var(--gradient-primary); transform: scaleX(0);
    transition: transform var(--transition);
}
.service-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-xl);
    border-color: transparent;
}
.service-card:hover::before { transform: scaleX(1); }
.service-icon {
    display: inline-flex; align-items: center; justify-content: center;
    width: 72px; height: 72px; border-radius: var(--radius-md);
    background: var(--color-primary-bg); color: var(--color-primary);
    margin-bottom: 20px; transition: all var(--transition);
}
.service-card:hover .service-icon {
    background: var(--gradient-primary); color: var(--color-white);
    box-shadow: var(--shadow-primary);
}
.service-title { font-size: 18px; margin-bottom: 4px; }
.service-title-en {
    font-size: 12px; color: var(--color-gray-light);
    font-family: var(--font-en); margin-bottom: 12px; text-transform: uppercase;
    letter-spacing: 0.06em;
}
.service-desc { font-size: 14px; color: var(--color-gray); line-height: 1.7; }

/* ==================== CASES ==================== */
.cases { background: var(--color-white); }
.cases-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.case-card {
    position: relative; background: var(--color-gray-bg);
    border-radius: var(--radius-lg); padding: 36px 28px;
    transition: all var(--transition); overflow: hidden;
    border: 1px solid var(--color-gray-border);
}
.case-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--color-primary-light);
}
.case-number {
    font-size: 64px; font-weight: 800; font-family: var(--font-en);
    color: rgba(26, 86, 219, 0.06); position: absolute;
    top: 12px; right: 20px; line-height: 1; pointer-events: none;
}
.case-content { position: relative; z-index: 1; }
.case-industry {
    display: inline-block; padding: 3px 12px;
    background: var(--color-primary-bg); color: var(--color-primary);
    border-radius: 50px; font-size: 12px; font-weight: 600; margin-bottom: 12px;
}
.case-client { font-size: 18px; margin-bottom: 10px; }
.case-desc { font-size: 14px; color: var(--color-gray); line-height: 1.7; margin-bottom: 16px; }
.case-tags { display: flex; flex-wrap: wrap; gap: 6px; }
.case-tag {
    padding: 4px 10px; background: var(--color-white);
    border-radius: var(--radius-sm); font-size: 12px;
    color: var(--color-dark-3); border: 1px solid var(--color-gray-border);
}

/* ==================== QUALIFICATION ==================== */
.qualification { background: var(--color-gray-bg); }
.qual-grid { display: grid; grid-template-columns: 1fr 380px; gap: 24px; }
.qual-card {
    background: var(--color-white); border-radius: var(--radius-lg);
    padding: 32px; box-shadow: var(--shadow-sm);
    border: 1px solid var(--color-gray-border);
}
.qual-card h3 { font-size: 18px; margin-bottom: 16px; }
.qual-tags { display: flex; flex-wrap: wrap; gap: 8px; }
.qual-tags span {
    padding: 6px 14px; background: var(--color-gray-bg);
    border-radius: 50px; font-size: 13px; color: var(--color-dark-3);
    border: 1px solid var(--color-gray-border); font-weight: 500;
}
.qual-tags span.licensed {
    background: #fef3c7; color: #92400e; border-color: #fcd34d; font-weight: 600;
}

/* ==================== CONTACT ==================== */
.contact { background: var(--color-white); }
.contact-grid {
    display: grid; grid-template-columns: 360px 1fr; gap: 40px;
    align-items: start;
}
.contact-info { display: flex; flex-direction: column; gap: 16px; }
.contact-info-card {
    display: flex; gap: 16px; padding: 20px;
    background: var(--color-gray-bg); border-radius: var(--radius-md);
    border: 1px solid var(--color-gray-border); transition: var(--transition);
}
.contact-info-card:hover { border-color: var(--color-primary-light); }
.contact-info-icon {
    width: 48px; height: 48px; border-radius: var(--radius-md);
    background: var(--color-primary-bg); color: var(--color-primary);
    display: flex; align-items: center; justify-content: center;
    flex-shrink: 0;
}
.contact-info-card h4 { font-size: 15px; margin-bottom: 4px; }
.contact-info-card p { font-size: 14px; color: var(--color-gray); }
.contact-form-wrapper {
    background: var(--color-gray-bg); border-radius: var(--radius-lg);
    padding: 36px; border: 1px solid var(--color-gray-border);
}
.contact-form h3 { font-size: 22px; margin-bottom: 4px; }
.contact-form > p { font-size: 14px; color: var(--color-gray); margin-bottom: 24px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; margin-bottom: 16px; }
.form-group { display: flex; flex-direction: column; gap: 6px; }
.form-group label { font-size: 14px; font-weight: 600; color: var(--color-dark-3); }
.form-group label span { color: var(--color-primary); }
.form-group input, .form-group textarea {
    padding: 12px 16px; border: 1.5px solid var(--color-gray-border);
    border-radius: var(--radius-md); font-size: 14px; font-family: var(--font-cn);
    transition: all var(--transition); background: var(--color-white);
    outline: none; resize: vertical;
}
.form-group input:focus, .form-group textarea:focus {
    border-color: var(--color-primary); box-shadow: 0 0 0 3px rgba(26, 86, 219, 0.1);
}
.form-group textarea { min-height: 100px; }

/* ==================== FOOTER ==================== */
.footer {
    background: var(--color-dark); color: var(--color-gray-light);
    padding: 60px 0 0;
}
.footer-grid {
    display: grid; grid-template-columns: 2fr 1fr 1fr 1.3fr; gap: 40px;
    padding-bottom: 40px; border-bottom: 1px solid rgba(255,255,255,0.08);
}
.footer-logo {
    display: flex; align-items: center; gap: 12px; margin-bottom: 12px;
}
.footer-logo strong { font-size: 18px; color: var(--color-white); display: block; }
.footer-logo small { font-size: 11px; color: var(--color-gray-light); font-family: var(--font-en); letter-spacing: 0.06em; }
.footer-desc { font-size: 14px; color: var(--color-gray); line-height: 1.7; }
.footer-col h4 { color: var(--color-white); font-size: 15px; margin-bottom: 16px; }
.footer-col ul { display: flex; flex-direction: column; gap: 8px; }
.footer-col ul li a { font-size: 14px; color: var(--color-gray-light); }
.footer-col ul li a:hover { color: var(--color-primary-light); }
.footer-contact p { font-size: 14px; margin-bottom: 6px; }
.footer-bottom {
    display: flex; flex-direction: column; align-items: center; text-align: center;
    padding: 20px 0; font-size: 13px; gap: 8px;
}
.footer-bottom p { margin: 0; }
.footer-bottom a { color: var(--color-gray-light); }
.footer-bottom a:hover { color: var(--color-primary-light); }

/* ==================== BACK TO TOP ==================== */
.back-to-top {
    position: fixed; bottom: 32px; right: 32px; z-index: 999;
    width: 44px; height: 44px; border-radius: 50%;
    background: var(--color-primary); color: var(--color-white); border: none;
    cursor: pointer; display: flex; align-items: center; justify-content: center;
    box-shadow: var(--shadow-primary); opacity: 0; visibility: hidden;
    transform: translateY(10px); transition: all var(--transition);
}
.back-to-top.visible { opacity: 1; visibility: visible; transform: translateY(0); }
.back-to-top:hover { background: var(--color-primary-dark); transform: translateY(-3px); }

/* ==================== RESPONSIVE ==================== */
@media (max-width: 1024px) {
    .services-grid { grid-template-columns: repeat(2, 1fr); }
    .cases-grid { grid-template-columns: repeat(2, 1fr); }
    .qual-grid { grid-template-columns: 1fr; }
    .contact-grid { grid-template-columns: 1fr; }
    .footer-grid { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 768px) {
    .header-inner { height: 64px; }
    .nav {
        position: fixed; top: 64px; left: 0; right: 0;
        background: rgba(15, 23, 42, 0.98); backdrop-filter: blur(16px);
        flex-direction: column; padding: 16px 24px; gap: 2px;
        transform: translateY(-120%); transition: transform 0.35s ease;
        border-bottom: 1px solid rgba(255,255,255,0.06);
    }
    .nav.open { transform: translateY(0); }
    .nav-link { padding: 14px 16px; font-size: 16px; border-radius: var(--radius-md); }
    .nav-toggle { display: flex; }
    .section { padding: 70px 0; }
    .about-grid { grid-template-columns: 1fr; gap: 36px; }
    .about-features { grid-template-columns: 1fr; }
    .services-grid { grid-template-columns: 1fr; }
    .cases-grid { grid-template-columns: 1fr; }
    .hero-stats { gap: 24px; }
    .hero-actions { flex-direction: column; align-items: center; }
    .form-row { grid-template-columns: 1fr; }
    .footer-grid { grid-template-columns: 1fr; gap: 32px; }
    .footer-bottom { flex-direction: column; text-align: center; }
}

@media (max-width: 480px) {
    .container { padding: 0 16px; }
    .hero-content { padding: 100px 16px 60px; }
    .contact-form-wrapper { padding: 24px; }
}