/* ============================================================
   中网互联 SSL 证书站 · 设计系统 (Design System)
   main.css — 变量 / 重置 / 排版 / 按钮 / 卡片 / 表单 / 徽章 / 工具类
   ============================================================ */

/* ---------- 1. 设计令牌（Design Tokens） ---------- */
:root {
  /* 品牌色 */
  --c-primary:        #1668DC;
  --c-primary-dark:   #0E4FA8;
  --c-primary-light:  #E8F1FE;
  --c-cyan:           #13C2C2;
  --c-cyan-light:     #E6FAFA;
  --c-accent:         #00B96B;   /* 安全绿 */
  --c-accent-light:   #E6F9F0;
  --c-warn:           #FA8C16;
  --c-warn-light:     #FFF4E6;
  --c-danger:         #F5222D;
  --c-danger-light:   #FFF1F0;

  /* 深色区（暗色系） */
  --c-dark-900:       #071322;
  --c-dark-800:       #0A1628;
  --c-dark-700:       #0F2035;
  --c-dark-600:       #16294A;
  --c-dark-line:      rgba(255,255,255,.10);
  --c-dark-text:      rgba(255,255,255,.72);
  --c-dark-text-dim:  rgba(255,255,255,.50);

  /* 中性色 */
  --c-ink:            #0D1B2A;
  --c-text:           #1F2D3D;
  --c-text-sub:       #5A6B7F;
  --c-text-mute:      #8A9AAB;
  --c-line:           #E4EAF1;
  --c-line-soft:      #EFF4F9;

  /* 背景 */
  --c-bg:             #FFFFFF;
  --c-bg-soft:        #F6F9FC;
  --c-bg-mute:        #EDF2F8;

  /* 渐变 */
  --g-brand:          linear-gradient(135deg, #1668DC 0%, #13C2C2 100%);
  --g-brand-soft:     linear-gradient(135deg, #E8F1FE 0%, #E6FAFA 100%);
  --g-dark:           linear-gradient(160deg, #0A1628 0%, #0F2035 60%, #123356 100%);
  --g-glow:           radial-gradient(60% 60% at 50% 0%, rgba(19,194,194,.28) 0%, rgba(22,104,220,.10) 45%, transparent 75%);
  --g-text:           linear-gradient(100deg, #38BDF8 0%, #13C2C2 55%, #4ADE9B 100%);
  --g-card-hover:     linear-gradient(135deg, rgba(22,104,220,.06), rgba(19,194,194,.06));

  /* 圆角 */
  --r-xs: 6px;
  --r-sm: 10px;
  --r-md: 14px;
  --r-lg: 20px;
  --r-xl: 28px;
  --r-full: 999px;

  /* 阴影 */
  --sh-xs:  0 1px 2px rgba(10,22,40,.06);
  --sh-sm:  0 2px 8px rgba(10,22,40,.06);
  --sh-md:  0 8px 24px rgba(10,22,40,.08);
  --sh-lg:  0 16px 48px rgba(10,22,40,.12);
  --sh-xl:  0 28px 72px rgba(10,22,40,.16);
  --sh-glow:0 12px 40px rgba(22,104,220,.28);

  /* 间距 */
  --s-1: 4px;  --s-2: 8px;  --s-3: 12px; --s-4: 16px;
  --s-5: 20px; --s-6: 24px; --s-8: 32px; --s-10: 40px;
  --s-12: 48px; --s-16: 64px; --s-20: 80px; --s-24: 96px;

  /* 字号 */
  --fs-xs: 12px; --fs-sm: 13px; --fs-base: 15px; --fs-md: 16px;
  --fs-lg: 18px; --fs-xl: 20px; --fs-2xl: 24px; --fs-3xl: 30px;
  --fs-4xl: 38px; --fs-5xl: 48px; --fs-6xl: 58px;

  /* 其它 */
  --w-container: 1240px;
  --w-narrow: 860px;
  --nav-h: 72px;
  --ease: cubic-bezier(.4,0,.2,1);
  --ease-out: cubic-bezier(.16,1,.3,1);
  --font: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI",
          "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  --font-mono: "SFMono-Regular", "JetBrains Mono", Consolas, "Liberation Mono", Menlo, monospace;
}

/* ---------- 2. 重置 ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; scroll-padding-top: 90px; }
body {
  margin: 0;
  font-family: var(--font);
  font-size: var(--fs-base);
  line-height: 1.7;
  color: var(--c-text);
  background: var(--c-bg);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  overflow-x: hidden;
}
h1,h2,h3,h4,h5,h6,p,figure,blockquote,dl,dd { margin: 0; }
ul,ol { margin: 0; padding: 0; list-style: none; }
img,svg,video { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; transition: color .2s var(--ease); }
button,input,select,textarea { font: inherit; color: inherit; }
button { cursor: pointer; background: none; border: none; padding: 0; }
table { border-collapse: collapse; width: 100%; }
:focus-visible { outline: 2px solid var(--c-primary); outline-offset: 3px; border-radius: 4px; }

/* ---------- 3. 排版 ---------- */
.h1, h1 { font-size: var(--fs-6xl); line-height: 1.12; font-weight: 800; letter-spacing: -.02em; color: var(--c-ink); }
.h2, h2 { font-size: var(--fs-4xl); line-height: 1.2;  font-weight: 800; letter-spacing: -.02em; color: var(--c-ink); }
.h3, h3 { font-size: var(--fs-2xl); line-height: 1.35; font-weight: 700; color: var(--c-ink); }
.h4, h4 { font-size: var(--fs-xl);  line-height: 1.4;  font-weight: 700; color: var(--c-ink); }
.h5, h5 { font-size: var(--fs-lg);  line-height: 1.5;  font-weight: 600; color: var(--c-ink); }
p { color: var(--c-text-sub); }
strong { font-weight: 700; color: var(--c-text); }
small { font-size: var(--fs-sm); }
code, kbd, pre { font-family: var(--font-mono); }

.txt-grad {
  background: var(--g-text);
  -webkit-background-clip: text; background-clip: text;
  -webkit-text-fill-color: transparent; color: transparent;
}
.txt-brand { color: var(--c-primary); }
.txt-mute  { color: var(--c-text-mute); }
.txt-up    { color: var(--c-danger); }  /* 涨=红（中国习惯） */
.txt-down  { color: #52C41A; }          /* 跌=绿 */

/* ---------- 4. 布局容器 ---------- */
.container { width: 100%; max-width: var(--w-container); margin: 0 auto; padding: 0 24px; }
.container-narrow { width: 100%; max-width: var(--w-narrow); margin: 0 auto; padding: 0 24px; }
.section { padding: var(--s-24) 0; }
.section-sm { padding: var(--s-16) 0; }
.section-soft { background: var(--c-bg-soft); }
.section-dark { background: var(--g-dark); color: #fff; }
.section-dark .h2, .section-dark h2, .section-dark .h3, .section-dark h3 { color: #fff; }
.section-dark p { color: var(--c-dark-text); }

/* 区块标题组 */
.sec-head { text-align: center; max-width: 720px; margin: 0 auto var(--s-16); }
.sec-head.left { text-align: left; margin-left: 0; }
.sec-tag {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: var(--fs-sm); font-weight: 600; letter-spacing: .08em;
  text-transform: uppercase; color: var(--c-primary);
  background: var(--c-primary-light); padding: 6px 14px;
  border-radius: var(--r-full); margin-bottom: var(--s-4);
}
.sec-tag.dot::before { content:""; width:6px; height:6px; border-radius:50%; background: var(--c-primary); }
.section-dark .sec-tag { background: rgba(19,194,194,.14); color: #4ADE9B; }
.sec-title { margin-bottom: var(--s-4); }
.sec-desc { font-size: var(--fs-md); color: var(--c-text-sub); }
.section-dark .sec-desc { color: var(--c-dark-text); }

/* ---------- 5. 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  height: 48px; padding: 0 26px; border-radius: var(--r-full);
  font-size: var(--fs-base); font-weight: 600; white-space: nowrap;
  transition: all .25s var(--ease); border: 1.5px solid transparent;
}
.btn svg { width: 18px; height: 18px; flex-shrink: 0; }
.btn-primary { background: var(--g-brand); color: #fff; box-shadow: var(--sh-glow); }
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 18px 46px rgba(22,104,220,.38); }
.btn-solid { background: var(--c-primary); color: #fff; }
.btn-solid:hover { background: var(--c-primary-dark); transform: translateY(-2px); }
.btn-accent { background: var(--c-accent); color: #fff; }
.btn-accent:hover { background: #009E5B; transform: translateY(-2px); }
.btn-ghost { border-color: var(--c-line); background: #fff; color: var(--c-text); }
.btn-ghost:hover { border-color: var(--c-primary); color: var(--c-primary); background: var(--c-primary-light); }
.btn-outline-light { border-color: rgba(255,255,255,.30); color: #fff; }
.btn-outline-light:hover { border-color: #fff; background: rgba(255,255,255,.10); }
.btn-light { background: #fff; color: var(--c-primary); }
.btn-light:hover { transform: translateY(-2px); box-shadow: var(--sh-lg); }
.btn-sm { height: 38px; padding: 0 18px; font-size: var(--fs-sm); }
.btn-lg { height: 56px; padding: 0 34px; font-size: var(--fs-md); }
.btn-block { width: 100%; }
.btn[disabled] { opacity: .5; pointer-events: none; }

/* 文字链接 */
.link-arrow { display: inline-flex; align-items: center; gap: 6px; font-weight: 600; color: var(--c-primary); }
.link-arrow svg { width: 16px; height: 16px; transition: transform .25s var(--ease); }
.link-arrow:hover svg { transform: translateX(4px); }

/* ---------- 6. 卡片 ---------- */
.card {
  background: #fff; border: 1px solid var(--c-line);
  border-radius: var(--r-lg); padding: var(--s-8);
  transition: transform .3s var(--ease), box-shadow .3s var(--ease), border-color .3s var(--ease);
}
.card-hover:hover { transform: translateY(-6px); box-shadow: var(--sh-lg); border-color: transparent; }
.card-glass {
  background: rgba(255,255,255,.06); border: 1px solid var(--c-dark-line);
  backdrop-filter: blur(14px); -webkit-backdrop-filter: blur(14px);
  border-radius: var(--r-lg); padding: var(--s-8);
}
.card-dark {
  background: rgba(255,255,255,.04); border: 1px solid var(--c-dark-line);
  border-radius: var(--r-lg); padding: var(--s-8);
  transition: all .3s var(--ease);
}
.card-dark:hover { background: rgba(255,255,255,.08); border-color: rgba(19,194,194,.4); transform: translateY(-4px); }

/* 渐变描边卡片 */
.card-grad { position: relative; background: #fff; border-radius: var(--r-lg); padding: var(--s-8); }
.card-grad::before {
  content: ""; position: absolute; inset: 0; border-radius: inherit; padding: 1.5px;
  background: var(--g-brand); -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor; mask-composite: exclude; opacity: 0; transition: opacity .3s var(--ease);
}
.card-grad:hover::before { opacity: 1; }

/* ---------- 7. 图标容器 ---------- */
.ico {
  width: 52px; height: 52px; border-radius: var(--r-md);
  display: flex; align-items: center; justify-content: center;
  background: var(--g-brand-soft); color: var(--c-primary); flex-shrink: 0;
}
.ico svg { width: 26px; height: 26px; }
.ico-lg { width: 64px; height: 64px; border-radius: var(--r-lg); }
.ico-lg svg { width: 32px; height: 32px; }
.ico-solid { background: var(--g-brand); color: #fff; }
.ico-green { background: var(--c-accent-light); color: var(--c-accent); }
.ico-warn  { background: var(--c-warn-light);   color: var(--c-warn); }
.ico-dark  { background: rgba(19,194,194,.14); color: #4ADE9B; }

/* ---------- 8. 徽章 / 标签 ---------- */
.badge {
  display: inline-flex; align-items: center; gap: 6px;
  font-size: var(--fs-xs); font-weight: 600; line-height: 1;
  padding: 6px 12px; border-radius: var(--r-full);
  background: var(--c-bg-mute); color: var(--c-text-sub);
}
.badge-brand { background: var(--c-primary-light); color: var(--c-primary); }
.badge-green { background: var(--c-accent-light); color: var(--c-accent); }
.badge-warn  { background: var(--c-warn-light);   color: var(--c-warn); }
.badge-dark  { background: rgba(255,255,255,.10); color: rgba(255,255,255,.85); }
.badge-red   { background: var(--c-danger-light); color: var(--c-danger); }
.badge-dot::before { content:""; width:6px; height:6px; border-radius:50%; background: currentColor; }

/* 标签胶囊（新闻分类、筛选） */
.chip {
  display: inline-flex; align-items: center; gap: 6px;
  height: 36px; padding: 0 18px; border-radius: var(--r-full);
  border: 1px solid var(--c-line); background: #fff;
  font-size: var(--fs-sm); font-weight: 500; color: var(--c-text-sub);
  transition: all .22s var(--ease); cursor: pointer;
}
.chip:hover { border-color: var(--c-primary); color: var(--c-primary); }
.chip.active { background: var(--c-primary); border-color: var(--c-primary); color: #fff; }

/* ---------- 9. 表单 ---------- */
.field { margin-bottom: var(--s-5); }
.label { display: block; font-size: var(--fs-sm); font-weight: 600; color: var(--c-text); margin-bottom: 8px; }
.label .req { color: var(--c-danger); }
.input, .select, .textarea {
  width: 100%; height: 48px; padding: 0 16px;
  border: 1.5px solid var(--c-line); border-radius: var(--r-sm);
  background: #fff; color: var(--c-text); font-size: var(--fs-base);
  transition: border-color .2s var(--ease), box-shadow .2s var(--ease);
}
.textarea { height: auto; min-height: 130px; padding: 14px 16px; resize: vertical; line-height: 1.7; }
.input:hover, .select:hover, .textarea:hover { border-color: #C7D3E0; }
.input:focus, .select:focus, .textarea:focus {
  outline: none; border-color: var(--c-primary); box-shadow: 0 0 0 4px rgba(22,104,220,.10);
}
.input::placeholder, .textarea::placeholder { color: var(--c-text-mute); }
.select { appearance: none; background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='16' height='16' viewBox='0 0 24 24' fill='none' stroke='%235A6B7F' stroke-width='2'%3E%3Cpath d='M6 9l6 6 6-6'/%3E%3C/svg%3E"); background-repeat: no-repeat; background-position: right 14px center; padding-right: 42px; }
.field-error .input, .field-error .select, .field-error .textarea { border-color: var(--c-danger); }
.err-msg { display: none; font-size: var(--fs-xs); color: var(--c-danger); margin-top: 6px; }
.field-error .err-msg { display: block; }
.form-note { font-size: var(--fs-xs); color: var(--c-text-mute); }
.checkbox { display: flex; align-items: flex-start; gap: 10px; font-size: var(--fs-sm); color: var(--c-text-sub); cursor: pointer; }
.checkbox input { width: 17px; height: 17px; margin-top: 3px; accent-color: var(--c-primary); flex-shrink: 0; }

/* 表单提交成功提示 */
.alert { display: none; align-items: center; gap: 12px; padding: 14px 18px; border-radius: var(--r-sm); font-size: var(--fs-sm); font-weight: 500; }
.alert.show { display: flex; }
.alert-success { background: var(--c-accent-light); color: #0A7B4C; border: 1px solid rgba(0,185,107,.25); }
.alert-error { background: var(--c-danger-light); color: #B01924; border: 1px solid rgba(245,34,45,.22); }
.alert svg { width: 20px; height: 20px; flex-shrink: 0; }

/* ---------- 10. 表格 ---------- */
.table-wrap { overflow-x: auto; border: 1px solid var(--c-line); border-radius: var(--r-lg); background: #fff; }
.tbl { width: 100%; min-width: 720px; font-size: var(--fs-sm); }
.tbl th, .tbl td { padding: 16px 20px; text-align: left; border-bottom: 1px solid var(--c-line-soft); }
.tbl thead th { background: var(--c-bg-soft); font-weight: 700; color: var(--c-ink); font-size: var(--fs-sm); white-space: nowrap; position: sticky; top: 0; z-index: 2; }
.tbl tbody tr:last-child td { border-bottom: none; }
.tbl tbody tr:hover { background: #FAFCFE; }
.tbl td.center, .tbl th.center { text-align: center; }
.tbl .yes { color: var(--c-accent); font-weight: 700; }
.tbl .no  { color: #C3CED9; }
.tbl-highlight { background: var(--c-primary-light) !important; }

/* 价格数字 */
.price { font-weight: 800; color: var(--c-ink); letter-spacing: -.02em; }
.price .cur { font-size: .55em; font-weight: 700; vertical-align: super; }
.price .unit { font-size: .4em; font-weight: 500; color: var(--c-text-mute); }
.price-lg { font-size: var(--fs-5xl); }

/* ---------- 11. 网格工具类 ---------- */
.grid { display: grid; gap: var(--s-6); }
.g-2 { grid-template-columns: repeat(2, 1fr); }
.g-3 { grid-template-columns: repeat(3, 1fr); }
.g-4 { grid-template-columns: repeat(4, 1fr); }
.g-5 { grid-template-columns: repeat(5, 1fr); }
.g-auto-280 { grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); }
.g-auto-320 { grid-template-columns: repeat(auto-fill, minmax(320px, 1fr)); }
.flex { display: flex; }
.items-center { align-items: center; }
.items-start { align-items: flex-start; }
.justify-between { justify-content: space-between; }
.justify-center { justify-content: center; }
.flex-wrap { flex-wrap: wrap; }
.gap-2 { gap: 8px; } .gap-3 { gap: 12px; } .gap-4 { gap: 16px; }
.gap-6 { gap: 24px; } .gap-8 { gap: 32px; }
.mt-2{margin-top:8px}.mt-3{margin-top:12px}.mt-4{margin-top:16px}.mt-5{margin-top:20px}
.mt-6{margin-top:24px}.mt-8{margin-top:32px}.mt-10{margin-top:40px}.mt-12{margin-top:48px}
.mb-0{margin-bottom:0}.mb-2{margin-bottom:8px}.mb-3{margin-bottom:12px}.mb-4{margin-bottom:16px}
.mb-5{margin-bottom:20px}.mb-6{margin-bottom:24px}.mb-8{margin-bottom:32px}.mb-10{margin-bottom:40px}
.text-center { text-align: center; }
.mx-auto { margin-left: auto; margin-right: auto; }
.relative { position: relative; }
.hidden { display: none !important; }
.sr-only { position:absolute; width:1px; height:1px; padding:0; margin:-1px; overflow:hidden; clip:rect(0,0,0,0); white-space:nowrap; border:0; }

/* ---------- 12. 分隔与装饰 ---------- */
.divider { height: 1px; background: var(--c-line); border: none; margin: var(--s-10) 0; }
.divider-dark { background: var(--c-dark-line); }
.dot-grid {
  background-image: radial-gradient(rgba(22,104,220,.16) 1px, transparent 1px);
  background-size: 22px 22px;
}
.grid-lines {
  background-image: linear-gradient(rgba(255,255,255,.045) 1px, transparent 1px),
                    linear-gradient(90deg, rgba(255,255,255,.045) 1px, transparent 1px);
  background-size: 56px 56px;
}

/* ---------- 13. 动画 ---------- */
@keyframes fadeUp { from { opacity:0; transform: translateY(24px); } to { opacity:1; transform:none; } }
@keyframes floatY { 0%,100% { transform: translateY(0); } 50% { transform: translateY(-12px); } }
@keyframes pulse { 0%,100% { opacity:1; } 50% { opacity:.45; } }
@keyframes spin { to { transform: rotate(360deg); } }
@keyframes dash { to { stroke-dashoffset: 0; } }

.reveal { opacity: 0; transform: translateY(28px); transition: opacity .7s var(--ease-out), transform .7s var(--ease-out); }
.reveal.in { opacity: 1; transform: none; }
.reveal-d1 { transition-delay: .08s; } .reveal-d2 { transition-delay: .16s; }
.reveal-d3 { transition-delay: .24s; } .reveal-d4 { transition-delay: .32s; }
.float-anim { animation: floatY 6s ease-in-out infinite; }

/* 滚动进度条 */
.scroll-progress { position: fixed; top: 0; left: 0; height: 3px; width: 0; background: var(--g-brand); z-index: 999; transition: width .1s linear; }

/* 返回顶部 */
.to-top {
  position: fixed; right: 28px; bottom: 28px; z-index: 900;
  width: 46px; height: 46px; border-radius: 50%;
  background: var(--c-primary); color: #fff;
  display: flex; align-items: center; justify-content: center;
  box-shadow: var(--sh-glow); opacity: 0; visibility: hidden;
  transform: translateY(14px); transition: all .3s var(--ease);
}
.to-top.show { opacity: 1; visibility: visible; transform: none; }
.to-top:hover { background: var(--c-primary-dark); }
.to-top svg { width: 20px; height: 20px; }

/* ---------- 14. 响应式 ---------- */
@media (max-width: 1199px) {
  :root { --fs-6xl: 46px; --fs-5xl: 40px; --fs-4xl: 32px; }
  .g-5 { grid-template-columns: repeat(3, 1fr); }
  .g-4 { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 991px) {
  :root { --fs-6xl: 38px; --fs-5xl: 34px; --fs-4xl: 28px; --fs-3xl: 25px; }
  .g-3, .g-5 { grid-template-columns: repeat(2, 1fr); }
  .section { padding: var(--s-16) 0; }
  .section-sm { padding: var(--s-12) 0; }
  .sec-head { margin-bottom: var(--s-10); }
}
@media (max-width: 767px) {
  :root { --fs-6xl: 30px; --fs-5xl: 28px; --fs-4xl: 24px; --fs-3xl: 21px; --fs-2xl: 20px; --nav-h: 62px; }
  body { font-size: 15px; }
  .container, .container-narrow { padding: 0 18px; }
  .g-2, .g-3, .g-4, .g-5, .g-auto-280, .g-auto-320 { grid-template-columns: 1fr; }
  .section { padding: var(--s-12) 0; }
  .section-sm { padding: var(--s-10) 0; }
  .card, .card-dark, .card-glass { padding: var(--s-6); }
  .btn { height: 46px; padding: 0 22px; }
  .btn-lg { height: 52px; }
  .to-top { right: 16px; bottom: 16px; width: 42px; height: 42px; }
  .flex-mobile-col { flex-direction: column; align-items: stretch !important; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: .01ms !important; transition-duration: .01ms !important; }
  .reveal { opacity: 1; transform: none; }
}

/* ---------- 15. 打印 ---------- */
@media print {
  .navbar, .to-top, .scroll-progress, .site-footer, .cta-band { display: none !important; }
  body { color: #000; }
}