/* ═══════════════════════════════════════════════════════════
   知维数智 — 对外宣传网站样式表
   经验与智能融合的项目管理服务
   ═══════════════════════════════════════════════════════════ */

/* === CSS Variables === */
:root {
  --ocean: #0066CC;
  --ocean-dark: #004C99;
  --ocean-light: #E6F0FA;
  --deep: #1a1a2e;
  --deep-light: #2d2d44;
  --gray-900: #1a1a1a;
  --gray-700: #4a4a4a;
  --gray-500: #888888;
  --gray-300: #cccccc;
  --gray-100: #f5f5f7;
  --white: #ffffff;
  --accent-gold: #D4A843;
  --success: #10b981;
  --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", sans-serif;
  --shadow-sm: 0 1px 3px rgba(0,0,0,.08);
  --shadow-md: 0 4px 16px rgba(0,0,0,.10);
  --shadow-lg: 0 8px 32px rgba(0,0,0,.12);
  --radius: 8px;
  --radius-lg: 16px;
  --max-width: 1200px;
}

/* === Reset === */
*,*::before,*::after{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth;font-size:16px}
body{font-family:var(--font-sans);color:var(--gray-900);line-height:1.7;background:var(--white);-webkit-font-smoothing:antialiased}
img{max-width:100%;height:auto;display:block}
a{color:var(--ocean);text-decoration:none;transition:color .2s}
a:hover{color:var(--ocean-dark)}
ul{list-style:none}

/* === Container === */
.container{width:100%;max-width:var(--max-width);margin:0 auto;padding:0 24px}
.container-sm{max-width:800px;margin:0 auto;padding:0 24px}

/* === Section === */
.section{padding:80px 0}
.section-gray{background:var(--gray-100)}
.section-ocean{background:var(--ocean);color:var(--white)}
.section-deep{background:var(--deep);color:var(--white)}
.section-title{font-size:2rem;font-weight:700;text-align:center;margin-bottom:12px;color:var(--deep)}
.section-subtitle{font-size:1.1rem;text-align:center;color:var(--gray-500);margin-bottom:48px;max-width:600px;margin-left:auto;margin-right:auto}
.section-ocean .section-title,.section-ocean .section-subtitle,
.section-deep .section-title,.section-deep .section-subtitle{color:var(--white)}

/* === Buttons === */
.btn{display:inline-flex;align-items:center;gap:8px;padding:12px 28px;border-radius:var(--radius);font-size:1rem;font-weight:600;cursor:pointer;border:none;transition:all .25s;text-align:center;justify-content:center}
.btn-primary{background:var(--ocean);color:var(--white)}
.btn-primary:hover{background:var(--ocean-dark);color:var(--white);transform:translateY(-1px);box-shadow:var(--shadow-md)}
.btn-outline{background:transparent;color:var(--ocean);border:2px solid var(--ocean)}
.btn-outline:hover{background:var(--ocean);color:var(--white)}
.btn-white{background:var(--white);color:var(--ocean)}
.btn-white:hover{background:var(--ocean-light);transform:translateY(-1px);box-shadow:var(--shadow-md)}
.btn-lg{padding:16px 36px;font-size:1.1rem}
.btn-sm{padding:8px 18px;font-size:.9rem}

/* === Navbar === */
.navbar{position:fixed;top:0;left:0;right:0;z-index:1000;padding:16px 0;transition:all .3s;background:transparent}
.navbar.scrolled{background:rgba(255,255,255,.96);backdrop-filter:blur(8px);box-shadow:var(--shadow-sm);padding:10px 0}
.navbar .container{display:flex;align-items:center;justify-content:space-between}
.nav-logo{font-size:1.3rem;font-weight:700;color:var(--white);display:flex;align-items:center;gap:8px}
.navbar.scrolled .nav-logo{color:var(--deep)}
.nav-logo span{color:var(--accent-gold)}
.nav-links{display:flex;gap:32px;align-items:center}
.nav-links a{color:rgba(255,255,255,.85);font-size:.95rem;font-weight:500;position:relative}
.navbar.scrolled .nav-links a{color:var(--gray-700)}
.nav-links a:hover{color:var(--white)}
.navbar.scrolled .nav-links a:hover{color:var(--ocean)}
.nav-links a::after{content:'';position:absolute;left:0;bottom:-4px;width:0;height:2px;background:var(--ocean);transition:width .3s}
.nav-links a:hover::after{width:100%}
.nav-cta{padding:8px 20px !important;background:var(--ocean);border-radius:var(--radius);color:var(--white) !important}
.nav-cta:hover{background:var(--ocean-dark) !important}
.nav-cta::after{display:none !important}
.nav-toggle{display:none;flex-direction:column;gap:5px;cursor:pointer;background:none;border:none;padding:4px}
.nav-toggle span{width:24px;height:2px;background:var(--white);transition:all .3s}
.navbar.scrolled .nav-toggle span{background:var(--deep)}

/* === Hero === */
.hero{min-height:100vh;display:flex;align-items:center;background:linear-gradient(135deg, var(--deep) 0%, #0f3460 40%, var(--ocean-dark) 100%);position:relative;overflow:hidden}
.hero::before{content:'';position:absolute;inset:0;background:url("data:image/svg+xml,%3Csvg width='60' height='60' viewBox='0 0 60 60' xmlns='http://www.w3.org/2000/svg'%3E%3Cg fill='none' fill-rule='evenodd'%3E%3Cg fill='%23ffffff' fill-opacity='0.03'%3E%3Cpath d='M36 34v-4h-2v4h-4v2h4v4h2v-4h4v-2h-4zm0-30V0h-2v4h-4v2h4v4h2V6h4V4h-4zM6 34v-4H4v4H0v2h4v4h2v-4h4v-2H6zM6 4V0H4v4H0v2h4v4h2V6h4V4H6z'/%3E%3C/g%3E%3C/g%3E%3C/svg%3E");opacity:.5}
.hero-content{position:relative;z-index:1;max-width:700px}
.hero h1{font-size:3.2rem;font-weight:800;color:var(--white);line-height:1.25;margin-bottom:20px}
.hero h1 span{color:var(--accent-gold)}
.hero p{font-size:1.2rem;color:rgba(255,255,255,.8);margin-bottom:36px;line-height:1.8}
.hero-actions{display:flex;gap:16px;flex-wrap:wrap}
.hero-stats{display:flex;gap:48px;margin-top:56px}
.hero-stat{text-align:center}
.hero-stat-num{font-size:2.4rem;font-weight:800;color:var(--accent-gold)}
.hero-stat-label{font-size:.9rem;color:rgba(255,255,255,.65);margin-top:4px}

/* === Cards === */
.cards{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}
.card{background:var(--white);border-radius:var(--radius-lg);padding:32px;box-shadow:var(--shadow-sm);transition:all .3s;border:1px solid var(--gray-100)}
.card:hover{transform:translateY(-4px);box-shadow:var(--shadow-lg)}
.card-icon{width:56px;height:56px;border-radius:var(--radius);display:flex;align-items:center;justify-content:center;font-size:1.6rem;margin-bottom:20px}
.card-icon.ocean{background:var(--ocean-light);color:var(--ocean)}
.card-icon.gold{background:#fef3c7;color:var(--accent-gold)}
.card-icon.green{background:#d1fae5;color:var(--success)}
.card h3{font-size:1.15rem;margin-bottom:8px;color:var(--deep)}
.card p{color:var(--gray-500);font-size:.95rem;line-height:1.7}

/* === Service Detail === */
.service-block{display:grid;grid-template-columns:1fr 1fr;gap:60px;align-items:center;padding:48px 0}
.service-block:nth-child(even){direction:rtl}
.service-block:nth-child(even) .service-text{direction:ltr}
.service-block+.service-block{border-top:1px solid var(--gray-100)}
.service-text h3{font-size:1.5rem;color:var(--deep);margin-bottom:16px}
.service-text p{margin-bottom:12px;color:var(--gray-700)}
.service-list{display:flex;flex-wrap:wrap;gap:8px;margin-top:16px}
.service-tag{background:var(--ocean-light);color:var(--ocean-dark);padding:6px 14px;border-radius:20px;font-size:.85rem;font-weight:500}
.service-visual{border-radius:var(--radius-lg);min-height:280px;display:flex;align-items:center;justify-content:center;text-align:center;padding:24px;overflow:hidden;position:relative}
.service-visual::after{content:'';position:absolute;width:200px;height:200px;border-radius:50%;background:rgba(255,255,255,.5);top:-40px;right:-40px}

/* === Project Cards === */
.project-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(340px,1fr));gap:24px}
.project-card{background:var(--white);border-radius:var(--radius-lg);overflow:hidden;box-shadow:var(--shadow-sm);transition:all .3s;border:1px solid var(--gray-100)}
.project-card:hover{transform:translateY(-4px);box-shadow:var(--shadow-lg)}
.project-image{height:200px;background:linear-gradient(135deg, var(--ocean), var(--ocean-dark));display:flex;align-items:center;justify-content:center;color:rgba(255,255,255,.6);font-size:.9rem}
.project-body{padding:24px}
.project-body h3{font-size:1.1rem;margin-bottom:8px;color:var(--deep)}
.project-body p{color:var(--gray-500);font-size:.9rem;margin-bottom:12px}
.project-tags{display:flex;gap:6px;flex-wrap:wrap}
.project-tag{background:var(--gray-100);padding:4px 10px;border-radius:4px;font-size:.8rem;color:var(--gray-700)}

/* === Knowledge Cards === */
.knowledge-list{display:flex;flex-direction:column;gap:20px}
.knowledge-item{display:flex;gap:20px;padding:24px;background:var(--white);border-radius:var(--radius);box-shadow:var(--shadow-sm);transition:all .3s}
.knowledge-item:hover{box-shadow:var(--shadow-md)}
.knowledge-date{font-size:.85rem;color:var(--gray-500);white-space:nowrap;min-width:100px}
.knowledge-content h4{font-size:1.05rem;margin-bottom:6px}
.knowledge-content p{font-size:.9rem;color:var(--gray-500)}
.knowledge-cat{display:inline-block;background:var(--ocean-light);color:var(--ocean);padding:2px 10px;border-radius:12px;font-size:.8rem;margin-top:8px}

/* === About Timeline === */
.timeline{position:relative;padding-left:32px}
.timeline::before{content:'';position:absolute;left:8px;top:0;bottom:0;width:2px;background:var(--gray-300)}
.timeline-item{position:relative;margin-bottom:32px}
.timeline-item::before{content:'';position:absolute;left:-28px;top:6px;width:14px;height:14px;border-radius:50%;background:var(--ocean);border:3px solid var(--white);box-shadow:0 0 0 3px var(--ocean)}
.timeline-year{font-size:.85rem;color:var(--ocean);font-weight:700;margin-bottom:4px}
.timeline-item h4{font-size:1rem;color:var(--deep);margin-bottom:4px}
.timeline-item p{font-size:.9rem;color:var(--gray-500)}

/* === Contact Form === */
.contact-grid{display:grid;grid-template-columns:1fr 1fr;gap:48px}
.form-group{margin-bottom:20px}
.form-group label{display:block;font-size:.9rem;font-weight:600;margin-bottom:6px;color:var(--gray-700)}
.form-group input,.form-group textarea,.form-group select{width:100%;padding:12px 16px;border:1px solid var(--gray-300);border-radius:var(--radius);font-size:1rem;font-family:var(--font-sans);transition:border-color .2s}
.form-group input:focus,.form-group textarea:focus,.form-group select:focus{outline:none;border-color:var(--ocean);box-shadow:0 0 0 3px var(--ocean-light)}
.form-group textarea{min-height:120px;resize:vertical}
.contact-info{padding:32px;background:var(--gray-100);border-radius:var(--radius-lg)}
.contact-info h3{margin-bottom:24px;color:var(--deep)}
.contact-info-item{display:flex;gap:12px;margin-bottom:20px;font-size:.95rem;color:var(--gray-700)}
.contact-info-item .icon{font-size:1.2rem;flex-shrink:0}
.qr-placeholder{width:160px;height:160px;background:var(--gray-300);border-radius:var(--radius);display:flex;align-items:center;justify-content:center;color:var(--gray-500);font-size:.85rem;margin-top:24px}

/* === CTA Section === */
.cta{text-align:center}
.cta h2{font-size:2rem;margin-bottom:12px}
.cta p{font-size:1.1rem;opacity:.85;margin-bottom:28px}

/* === Footer === */
.footer{background:var(--deep);color:rgba(255,255,255,.65);padding:48px 0 24px}
.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr 1fr;gap:40px;margin-bottom:40px}
.footer h4{color:var(--white);font-size:1rem;margin-bottom:16px}
.footer a{color:rgba(255,255,255,.55);font-size:.9rem;display:block;margin-bottom:8px;transition:color .2s}
.footer a:hover{color:var(--white)}
.footer-brand p{font-size:.9rem;margin-top:12px;line-height:1.7}
.footer-bottom{border-top:1px solid rgba(255,255,255,.1);padding-top:24px;display:flex;justify-content:space-between;font-size:.85rem;flex-wrap:wrap;gap:12px}

/* === Utilities === */
.text-center{text-align:center}
.text-ocean{color:var(--ocean)}
.text-gold{color:var(--accent-gold)}
.mt-0{margin-top:0}
.mt-20{margin-top:20px}
.mt-40{margin-top:40px}
.mb-20{margin-bottom:20px}
.hidden{display:none}

/* === Toast === */
.toast{position:fixed;bottom:24px;right:24px;background:var(--success);color:var(--white);padding:14px 24px;border-radius:var(--radius);font-weight:600;z-index:9999;animation:fadeInUp .3s ease-out;box-shadow:var(--shadow-md)}
.toast.error{background:#ef4444}

/* === Animations === */
@keyframes fadeInUp{from{opacity:0;transform:translateY(20px)}to{opacity:1;transform:translateY(0)}}
.anim-fade{opacity:0;transform:translateY(20px);transition:all .6s ease-out}
.anim-fade.visible{opacity:1;transform:translateY(0)}

/* ═══════════════════════════════════════════════════════════
   Responsive — Tablet (768px)
   ═══════════════════════════════════════════════════════════ */
@media(max-width:768px){
  .hero h1{font-size:2.2rem}
  .hero p{font-size:1rem}
  .hero-stats{gap:24px;flex-wrap:wrap}
  .hero-stat-num{font-size:1.8rem}
  .cards{grid-template-columns:1fr}
  .service-block{grid-template-columns:1fr;gap:32px}
  .service-block:nth-child(even){direction:ltr}
  .contact-grid{grid-template-columns:1fr}
  .footer-grid{grid-template-columns:1fr 1fr}
  .project-grid{grid-template-columns:1fr}
  .section-title{font-size:1.6rem}
  .section{padding:56px 0}
  .nav-links{display:none;position:absolute;top:100%;left:0;right:0;background:var(--white);flex-direction:column;padding:20px 24px;box-shadow:var(--shadow-md);gap:16px}
  .nav-links.active{display:flex}
  .nav-links a{color:var(--gray-700) !important}
  .nav-toggle{display:flex}
  .knowledge-item{flex-direction:column;gap:8px}
}

/* ═══════════════════════════════════════════════════════════
   Responsive — Mobile (480px)
   ═══════════════════════════════════════════════════════════ */
@media(max-width:480px){
  .hero h1{font-size:1.8rem}
  .hero-actions{flex-direction:column}
  .hero-actions .btn{width:100%}
  .cards{grid-template-columns:1fr}
  .footer-grid{grid-template-columns:1fr}
  .footer-bottom{flex-direction:column;text-align:center}
  .section-title{font-size:1.4rem}
  .container{padding:0 16px}
  .card{padding:24px}
  .project-grid{grid-template-columns:1fr}
  .btn-lg{padding:14px 24px;font-size:1rem}
}