/* ========================================
   迪克新材料(天津)有限公司 - 化工原材料手机网站
   红色主题 · 简约大方 · 移动优先
   ======================================== */

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

:root {
    --red-50:  #FFF0F0;
    --red-100: #FFD6D6;
    --red-200: #FFB3B3;
    --red-400: #FF5F52;
    --red-500: #E53935;
    --red-600: #C62828;
    --red-700: #B71C1C;
    --red-800: #8E0000;
    --red-900: #5A0000;
    --white:   #FFFFFF;
    --gray-50: #FAFAFA;
    --gray-100:#F0F0F0;
    --gray-200:#E0E0E0;
    --gray-300:#CCCCCC;
    --gray-400:#AAAAAA;
    --gray-500:#888888;
    --gray-700:#555555;
    --gray-800:#333333;
    --gray-900:#1A1A1A;
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    --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 28px rgba(0,0,0,0.12);
    --transition: 0.25s cubic-bezier(0.4,0,0.2,1);
}

html { scroll-behavior: smooth; -webkit-tap-highlight-color: transparent; }

body {
    font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
    font-size: 17px; line-height: 1.7; color: var(--gray-900);
    background: var(--gray-50); overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

img { max-width:100%; height:auto; display:block; }
a { color: var(--red-600); text-decoration: none; transition: color var(--transition); }
a:active { color: var(--red-800); }

/* ---------- Header ---------- */
.site-header {
    position: sticky; top:0; z-index:100;
    background: var(--white); padding: 10px 16px;
    display: flex; align-items: center; justify-content: space-between;
    border-bottom: 1px solid var(--gray-200);
}

.header-left { display:flex; align-items:center; gap:10px; }
.header-logo {
    width: 36px; height: 36px; border-radius: var(--radius-sm);
    background: linear-gradient(135deg, var(--red-600), var(--red-400));
    display: flex; align-items: center; justify-content: center;
    color: white; font-size: 16px; font-weight: 700;
}
.header-brand .brand-name { font-size:19px; font-weight:700; color:var(--gray-900); line-height:1.2; }
.header-brand .brand-slogan { font-size:13px; color:var(--gray-500); }

.nav-links { display:flex; gap:6px; }
.nav-links a {
    padding: 8px 14px; border-radius: 20px; font-size: 16px; font-weight: 500;
    color: var(--gray-700); transition: all var(--transition);
}
.nav-links a.active, .nav-links a:hover {
    background: var(--red-50); color: var(--red-600);
}

.menu-toggle { display:none; width:36px; height:36px; border:none; background:none;
    flex-direction:column; justify-content:center; gap:5px; cursor:pointer; padding:6px; }
.menu-toggle span { display:block; width:100%; height:2px; background:var(--gray-800);
    border-radius:1px; transition:all var(--transition); }
.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); }

.mobile-nav {
    position:fixed; top:57px; left:0; right:0; bottom:0; z-index:99;
    background: rgba(0,0,0,0.45); opacity:0; visibility:hidden; transition:all var(--transition);
}
.mobile-nav.active { opacity:1; visibility:visible; }
.mobile-nav-inner { background:var(--white); padding:8px 0; transform:translateY(-8px); transition:transform var(--transition); }
.mobile-nav.active .mobile-nav-inner { transform:translateY(0); }
.mobile-nav a {
    display:block; padding:14px 24px; color:var(--gray-800); font-size:17px;
    border-left:3px solid transparent; transition:all var(--transition);
}
.mobile-nav a.active, .mobile-nav a:active { background:var(--red-50); color:var(--red-600); border-left-color:var(--red-600); }

/* ---------- Page Banner ---------- */
.page-banner {
    background: linear-gradient(135deg, var(--red-700) 0%, var(--red-500) 50%, var(--red-400) 100%);
    color: var(--white); text-align: center; padding: 36px 20px;
    position: relative; overflow: hidden;
}
.page-banner::after {
    content:''; position:absolute; bottom:-30px; left:0; right:0; height:60px;
    background: var(--gray-50); border-radius: 50% 50% 0 0;
}
.page-banner-content { position:relative; z-index:1; }
.page-banner h1 { font-size: 28px; font-weight: 700; margin-bottom: 6px; }
.page-banner p { font-size: 16px; opacity:0.85; }

/* ---------- Home Hero ---------- */
.hero {
    background: linear-gradient(160deg, var(--red-800) 0%, var(--red-600) 40%, var(--red-500) 100%);
    color:var(--white); text-align:center; padding:50px 20px 40px;
    position:relative; overflow:hidden;
}
.hero::before {
    content:''; position:absolute; top:-30%; left:-30%; width:160%; height:160%;
    background: radial-gradient(circle at 30% 40%, rgba(255,255,255,0.06) 0%, transparent 60%);
}
.hero-badge {
    display:inline-block; background:rgba(255,255,255,0.18); backdrop-filter:blur(10px);
    padding:4px 16px; border-radius:50px; font-size:14px; margin-bottom:16px;
    border: 1px solid rgba(255,255,255,0.2);
}
.hero h1 { font-size:30px; font-weight:700; margin-bottom:10px; position:relative; }
.hero p { font-size:16px; opacity:0.88; line-height:1.7; margin-bottom:24px; position:relative; max-width:360px; margin-left:auto; margin-right:auto; }
.hero-buttons { display:flex; gap:12px; justify-content:center; flex-wrap:wrap; position:relative; }
.btn { display:inline-block; padding:12px 30px; border-radius:50px; font-size:16px; font-weight:600;
    transition:all var(--transition); text-align:center; border:none; cursor:pointer; }
.btn-white { background:var(--white); color:var(--red-600); box-shadow:0 4px 16px rgba(0,0,0,0.15); }
.btn-white:active { transform:scale(0.96); }
.btn-outline { background:transparent; color:var(--white); border:1.5px solid rgba(255,255,255,0.5); }
.btn-outline:active { background:rgba(255,255,255,0.1); }
.btn-red { background:linear-gradient(135deg, var(--red-600), var(--red-500)); color:white; box-shadow:0 4px 16px rgba(198,40,40,0.25); }
.btn-red:active { transform:scale(0.96); }

/* ---------- Section Common ---------- */
.section-padding { padding: 44px 16px; }
.section-white { background: var(--white); }
.section-header { text-align:center; margin-bottom:28px; }
.section-tag {
    display:inline-block; background:var(--red-50); color:var(--red-600);
    padding:4px 14px; border-radius:50px; font-size:14px; font-weight:600; margin-bottom:8px;
}
.section-title { font-size:26px; font-weight:700; color:var(--gray-900); margin-bottom:6px; }
.section-subtitle { font-size:15px; color:var(--gray-500); }

/* ---------- Stats Bar ---------- */
.stats-bar { display:grid; grid-template-columns:repeat(3,1fr); gap:12px; max-width:420px; margin:0 auto; }
.stat-card { background:var(--white); border-radius:var(--radius-md); padding:18px 10px; text-align:center; box-shadow:var(--shadow-sm); }
.stat-number { font-size:30px; font-weight:700; color:var(--red-600); line-height:1.1; }
.stat-label { font-size:14px; color:var(--gray-500); margin-top:4px; }

/* ---------- Category Cards ---------- */
.category-grid { display:grid; grid-template-columns:1fr; gap:12px; }
.category-card {
    background:var(--white); border-radius:var(--radius-md); padding:20px 16px;
    box-shadow:var(--shadow-sm); display:flex; align-items:center; gap:14px;
    transition:all var(--transition); border-left:4px solid var(--red-600);
}
.category-card:active { transform:translateX(4px); box-shadow:var(--shadow-md); }
.category-icon { width:44px; height:44px; border-radius:var(--radius-sm); background:var(--red-50);
    display:flex; align-items:center; justify-content:center; font-size:24px; flex-shrink:0; }
.category-info h4 { font-size:17px; font-weight:600; color:var(--gray-900); margin-bottom:2px; }
.category-info p { font-size:14px; color:var(--gray-500); }
.category-arrow { margin-left:auto; color:var(--gray-300); font-size:20px; }

/* ---------- Products Grid ---------- */
.product-list { display:flex; flex-direction:column; gap:10px; }
.product-item {
    background:var(--white); border-radius:var(--radius-md); padding:16px;
    box-shadow:var(--shadow-sm); display:flex; align-items:center; gap:12px;
    transition:all var(--transition);
}
.product-item:active { background:var(--red-50); }
.product-badge {
    width:40px; height:40px; border-radius:50%; background:linear-gradient(135deg, var(--red-600), var(--red-500));
    color:white; display:flex; align-items:center; justify-content:center; font-size:14px; font-weight:700; flex-shrink:0;
}
.product-main { flex:1; min-width:0; }
.product-name { font-size:17px; font-weight:600; color:var(--gray-900); margin-bottom:4px; }
.product-meta { display:flex; flex-wrap:wrap; gap:6px; }
.product-tag { font-size:13px; color:var(--gray-500); background:var(--gray-100); padding:2px 8px; border-radius:4px; }
.product-arrow { color:var(--gray-300); font-size:18px; flex-shrink:0; }

/* ---------- Product Detail ---------- */
.detail-card {
    background:var(--white); border-radius:var(--radius-lg); padding:24px 20px; box-shadow:var(--shadow-md);
    margin-bottom: 28px;
}
.detail-title { font-size:24px; font-weight:700; color:var(--red-600); margin-bottom:16px; }
.detail-grid { display:grid; grid-template-columns:1fr 1fr; gap:12px; }
.detail-item { background:var(--gray-50); border-radius:var(--radius-sm); padding:12px; }
.detail-label { font-size:13px; color:var(--gray-500); margin-bottom:3px; text-transform:uppercase; letter-spacing:0.5px; }
.detail-value { font-size:16px; font-weight:600; color:var(--gray-900); }
.detail-actions { margin-top:20px; display:flex; gap:10px; }
.detail-actions .btn { flex:1; text-align:center; }

/* ---------= About Page ========== */
.about-intro { text-align:center; }
.about-emblem {
    width:100px; height:100px; margin:0 auto 20px;
    background:linear-gradient(135deg, var(--red-600),var(--red-400)); border-radius:50%;
    display:flex; align-items:center; justify-content:center; font-size:44px;
    box-shadow:0 8px 28px rgba(198,40,40,0.22);
}
.about-desc { font-size:16px; color:var(--gray-700); line-height:1.85; max-width:400px; margin:0 auto 24px; }

.advantage-list { display:flex; flex-direction:column; gap:10px; max-width:420px; margin:0 auto; }
.advantage-item {
    display:flex; align-items:flex-start; gap:12px;
    background:var(--white); border-radius:var(--radius-md); padding:16px; box-shadow:var(--shadow-sm);
}
.advantage-check {
    width:28px; height:28px; border-radius:50%; background:var(--red-600);
    color:white; display:flex; align-items:center; justify-content:center; font-size:16px; flex-shrink:0; margin-top:2px;
}
.advantage-text h4 { font-size:16px; font-weight:600; color:var(--gray-900); margin-bottom:3px; }
.advantage-text p { font-size:14px; color:var(--gray-500); line-height:1.5; }

/* ---------- Contact Page ---------- */
.contact-card {
    background:var(--white); border-radius:var(--radius-lg); padding:24px 20px; box-shadow:var(--shadow-md);
    max-width:460px; margin:0 auto;
}
.form-group { margin-bottom:14px; }
.form-group label { display:block; font-size:15px; font-weight:600; color:var(--gray-800); margin-bottom:5px; }
.form-group input, .form-group select, .form-group textarea {
    width:100%; padding:12px 14px; border:1.5px solid var(--gray-200); border-radius:var(--radius-sm);
    font-size:16px; font-family:inherit; color:var(--gray-900); background:var(--gray-50);
    transition:all var(--transition); outline:none; -webkit-appearance:none;
}
.form-group input:focus, .form-group select:focus, .form-group textarea:focus {
    border-color:var(--red-500); background:var(--white); box-shadow:0 0 0 3px rgba(198,40,40,0.08);
}
.form-group textarea { min-height:100px; resize:vertical; }
.form-group select { cursor:pointer; background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8'%3E%3Cpath d='M1 1l5 5 5-5' fill='none' stroke='%23888' stroke-width='2'/%3E%3C/svg%3E"); background-repeat:no-repeat; background-position:right 14px center; padding-right:36px; }

.contact-info-cards { display:flex; flex-direction:column; gap:10px; max-width:460px; margin:24px auto 0; }
.info-card { display:flex; align-items:center; gap:12px; padding:14px 16px; background:var(--white); border-radius:var(--radius-sm); box-shadow:var(--shadow-sm); }
.info-card-icon { width:36px; height:36px; border-radius:50%; background:var(--red-50); display:flex; align-items:center; justify-content:center; font-size:18px; flex-shrink:0; }
.info-card-text { font-size:15px; color:var(--gray-800); }

/* ---------- Category Nav (Products Page) ---------- */
.cat-nav {
    display:flex; gap:8px; overflow-x:auto; padding:16px; -webkit-overflow-scrolling:touch;
    scrollbar-width:none;
}
.cat-nav::-webkit-scrollbar { display:none; }
.cat-nav a {
    flex-shrink:0; padding:8px 18px; border-radius:50px; font-size:15px; font-weight:500;
    color:var(--gray-700); background:var(--white); box-shadow:var(--shadow-sm);
    transition:all var(--transition); white-space:nowrap;
}
.cat-nav a.active, .cat-nav a:hover { background:var(--red-600); color:white; }

/* ---------- Footer ---------- */
.site-footer { background:var(--gray-900); color:var(--gray-400); padding:32px 18px 24px; }
.footer-top { display:flex; flex-direction:column; gap:20px; margin-bottom:24px; }
.footer-brand h3 { font-size:19px; font-weight:700; color:white; margin-bottom:6px; }
.footer-brand p { font-size:14px; line-height:1.6; }
.footer-links h4 { font-size:15px; font-weight:600; color:white; margin-bottom:10px; }
.footer-links a { display:block; font-size:15px; color:var(--gray-400); padding:4px 0; transition:color var(--transition); }
.footer-links a:active { color:var(--red-400); }
.footer-bottom { border-top:1px solid rgba(255,255,255,0.08); padding-top:16px; text-align:center; }
.footer-bottom p { font-size:13px; }

/* ---------= Toast ========== */
.toast {
    position:fixed; top:20px; left:50%; transform:translateX(-50%) translateY(-120px);
    background:var(--gray-900); color:white; padding:11px 22px; border-radius:50px;
    font-size:16px; font-weight:500; z-index:200; box-shadow:var(--shadow-lg);
    transition:transform var(--transition);
}
.toast.show { transform:translateX(-50%) translateY(0); }
.toast.success { background:#2E7D32; }
.toast.error { background:var(--red-600); }

/* ---------- Back to Top ---------- */
.back-to-top {
    position:fixed; bottom:20px; right:16px; width:42px; height:42px;
    border-radius:50%; background:var(--red-600); color:white; border:none; font-size:18px;
    cursor:pointer; box-shadow:0 4px 14px rgba(198,40,40,0.3); z-index:50;
    opacity:0; visibility:hidden; transform:translateY(16px);
    transition:all var(--transition); display:flex; align-items:center; justify-content:center;
}
.back-to-top.visible { opacity:1; visibility:visible; transform:translateY(0); }
.back-to-top:active { transform:scale(0.88); }

/* ---------- Animations ---------- */
.fade-up { animation: fadeInUp 0.5s ease both; }
@keyframes fadeInUp { from { opacity:0; transform:translateY(20px); } to { opacity:1; transform:translateY(0); } }

/* ---------- Tablet+ ---------- */
@media (min-width:640px) {
    .category-grid { grid-template-columns:repeat(2,1fr); max-width:680px; margin:0 auto; }
    .product-list { max-width:560px; margin:0 auto; }
    .stats-bar { max-width:500px; }
    .hero h1 { font-size:36px; }
    .section-padding { padding:56px 28px; }
    .cat-nav { justify-content:center; }
    .footer-top { flex-direction:row; justify-content:space-between; max-width:600px; margin-left:auto; margin-right:auto; }
}

@media (min-width:1024px) {
    .category-grid { grid-template-columns:repeat(3,1fr); max-width:960px; }
}

/* ---------- Mobile (default: hide desktop nav, show hamburger) ---------- */
@media (max-width: 639px) {
    .nav-links { display:none; }
    .menu-toggle { display:flex; }
}

/* ---------- Inline Page Nav Highlight ---------- */
.nav-links a { position:relative; }