/* ============================================================
   张老师官网 · 品牌样式
   视觉规范锁定自「建哥设计」：品牌红 #BE0000 / 鹅黄 #F2D06B / 思源黑体
   范式：苹果官网式分屏叙事 —— 一屏一件事，大留白、大字、大图
   ============================================================ */

:root {
  --brand: #BE0000;
  --brand-deep: #A31621;
  --brand-bright: #D63230;
  --accent: #F2D06B;
  --ink: #1A1F24;
  --ink-2: #3A424A;
  --ink-3: #9AA3AB;
  --bg: #FFFFFF;
  --soft: #F7F7F8;
  --line: #E7E8EA;
  --radius: 18px;
  --max: 1120px;
}

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

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  font-family: "Source Han Sans CN", "Noto Sans SC", "Microsoft YaHei", "PingFang SC", sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.7;
  font-size: 17px;
  overflow-x: hidden;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }

/* ---------- 导航 ---------- */
.nav {
  position: sticky; top: 0; z-index: 100;
  background: rgba(255,255,255,.86);
  backdrop-filter: saturate(180%) blur(20px);
  -webkit-backdrop-filter: saturate(180%) blur(20px);
  border-bottom: 1px solid var(--line);
}
.nav-inner {
  max-width: var(--max); margin: 0 auto; padding: 14px 24px;
  display: flex; align-items: center; justify-content: space-between; gap: 20px;
}
.brandmark { display: flex; align-items: center; gap: 10px; font-weight: 800; font-size: 19px; letter-spacing: .5px; }
.brandmark .dot { width: 12px; height: 12px; border-radius: 50%; background: var(--brand); }
.brandmark span.sub { font-weight: 500; font-size: 12px; color: var(--ink-3); letter-spacing: 2px; }
.nav-links { display: flex; gap: 26px; font-size: 15px; color: var(--ink-2); }
.nav-links a:hover { color: var(--brand); }
.nav-cta {
  background: var(--brand); color: #fff; padding: 9px 20px; border-radius: 999px;
  font-size: 15px; font-weight: 600; white-space: nowrap;
}
.nav-cta:hover { background: var(--brand-deep); }
@media (max-width: 820px) {
  .nav-links { display: none; }
}

/* ---------- 通用屏 ---------- */
section { padding: 96px 24px; }
.wrap { max-width: var(--max); margin: 0 auto; }
.eyebrow {
  display: inline-block; font-size: 13px; letter-spacing: 3px; font-weight: 700;
  color: var(--brand); text-transform: uppercase; margin-bottom: 18px;
}
.eyebrow.accent { color: #8a6a00; }
h1, h2, h3 { line-height: 1.22; letter-spacing: -.5px; font-weight: 800; }
h1 { font-size: clamp(34px, 5.4vw, 64px); }
h2 { font-size: clamp(28px, 3.8vw, 46px); }
h3 { font-size: clamp(20px, 2.2vw, 26px); }
.lead { font-size: clamp(17px, 1.5vw, 21px); color: var(--ink-2); max-width: 760px; }
.muted { color: var(--ink-3); font-size: 15px; }
.center { text-align: center; }
.center .lead { margin-left: auto; margin-right: auto; }

/* 结论句条 */
.answer {
  border-left: 4px solid var(--brand); background: var(--soft);
  padding: 16px 22px; border-radius: 0 12px 12px 0;
  font-size: 17px; color: var(--ink); margin-top: 22px; max-width: 820px;
}
.answer b { color: var(--brand-deep); }

/* ---------- 按钮 ---------- */
.cta-row { display: flex; flex-wrap: wrap; gap: 14px; margin-top: 30px; align-items: center; }
.btn {
  display: inline-block; padding: 14px 30px; border-radius: 999px;
  font-weight: 700; font-size: 16px; transition: .18s;
}
.btn-primary { background: var(--brand); color: #fff; }
.btn-primary:hover { background: var(--brand-deep); transform: translateY(-1px); }
.btn-ghost { color: var(--brand); font-weight: 600; }
.btn-ghost::after { content: " ›"; }
.btn-ghost:hover { text-decoration: underline; }
.btn-outline { border: 1.5px solid var(--ink); color: var(--ink); }
.btn-outline:hover { background: var(--ink); color: #fff; }

/* ---------- Hero ---------- */
.hero {
  background: linear-gradient(135deg, #C40F0F 0%, #BE0000 55%, #8F0000 100%);
  color: #fff; padding: 130px 24px 110px; text-align: center;
  position: relative; overflow: hidden;
}
.hero::after {
  content: ""; position: absolute; inset: 0;
  background: radial-gradient(60% 60% at 50% 0%, rgba(255,255,255,.14), transparent 70%);
  pointer-events: none;
}
.hero .wrap { position: relative; z-index: 2; }
.hero .tag {
  display: inline-block; border: 1px solid rgba(255,255,255,.5); color: #fff;
  padding: 7px 18px; border-radius: 999px; font-size: 14px; letter-spacing: 2px; margin-bottom: 26px;
}
.hero h1 { color: #fff; }
.hero .hero-sub {
  font-size: clamp(18px, 2vw, 24px); color: #FFE9C8; margin: 24px auto 0; max-width: 820px; font-weight: 600;
}
.hero .hero-sub .hl { color: var(--accent); }
.hero .meta { margin-top: 34px; display: flex; gap: 26px; justify-content: center; flex-wrap: wrap; color: rgba(255,255,255,.85); font-size: 15px; }
.hero .meta b { color: var(--accent); font-size: 22px; display: block; }
.hero .cta-row { justify-content: center; }
.hero .btn-primary { background: #fff; color: var(--brand); }
.hero .btn-primary:hover { background: var(--accent); color: var(--brand); }
.hero .btn-ghost { color: #fff; }

/* ---------- 卡片网格 ---------- */
.grid { display: grid; gap: 20px; margin-top: 44px; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-5 { grid-template-columns: repeat(5, 1fr); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
@media (max-width: 900px) { .grid-3, .grid-5 { grid-template-columns: 1fr 1fr; } }
@media (max-width: 620px) { .grid-3, .grid-5, .grid-2 { grid-template-columns: 1fr; } }

.card {
  border: 1px solid var(--line); border-radius: var(--radius); padding: 30px 26px;
  background: #fff; transition: .2s;
}
.card:hover { border-color: var(--brand); transform: translateY(-3px); box-shadow: 0 14px 40px rgba(190,0,0,.07); }
.card .num { font-size: 15px; font-weight: 800; color: var(--brand); letter-spacing: 1px; }
.card h3 { margin: 12px 0 10px; }
.card p { color: var(--ink-2); font-size: 15.5px; }
.card .concl { margin-top: 14px; font-size: 14px; color: var(--brand-deep); font-weight: 600; }

/* 环卡片 */
.ring {
  border-radius: var(--radius); padding: 26px 22px; color: #fff;
  background: linear-gradient(160deg, #BE0000, #8F0000); min-height: 210px;
  display: flex; flex-direction: column; justify-content: space-between;
}
.ring:nth-child(even) { background: linear-gradient(160deg, #A31621, #6f0d16); }
.ring .rno { font-size: 13px; letter-spacing: 2px; opacity: .8; }
.ring h3 { color: #fff; font-size: 21px; margin: 10px 0; }
.ring p { font-size: 14.5px; color: rgba(255,255,255,.88); }
.ring .rtag { margin-top: 14px; display: inline-block; background: var(--accent); color: #5a4400; font-size: 12px; font-weight: 700; padding: 4px 12px; border-radius: 999px; align-self: flex-start; }

/* 数字块 */
.stat { text-align: center; padding: 10px; }
.stat .big { font-size: clamp(38px, 5vw, 62px); font-weight: 800; color: var(--brand); letter-spacing: -2px; line-height: 1; }
.stat .lbl { margin-top: 10px; color: var(--ink-2); font-size: 15px; }

/* 深色/品牌底屏 */
.dark { background: var(--brand); color: #fff; }
.dark h2, .dark h3 { color: #fff; }
.dark .lead { color: rgba(255,255,255,.9); }
.dark .answer { background: rgba(255,255,255,.1); border-left-color: var(--accent); color: #fff; }
.dark .answer b { color: var(--accent); }
.dark .btn-primary { background: #fff; color: var(--brand); }
.dark .btn-ghost { color: var(--accent); }

.soft { background: var(--soft); }

/* ---------- FAQ ---------- */
.faq-item { border-bottom: 1px solid var(--line); padding: 24px 0; }
.faq-item h3 { font-size: 19px; margin-bottom: 10px; color: var(--ink); }
.faq-item p { color: var(--ink-2); font-size: 16px; }
.faq-item .q-tag { color: var(--brand); font-weight: 800; margin-right: 8px; }

/* ---------- 页脚 ---------- */
footer { background: #17191C; color: #c8ccd1; padding: 60px 24px 34px; font-size: 14.5px; }
footer .cols { max-width: var(--max); margin: 0 auto; display: grid; grid-template-columns: 1.4fr 1fr 1fr; gap: 40px; }
footer h4 { color: #fff; font-size: 15px; margin-bottom: 14px; letter-spacing: 1px; }
footer a { color: #c8ccd1; }
footer a:hover { color: var(--accent); }
footer ul { list-style: none; }
footer li { margin-bottom: 9px; }
footer .foot-slogan {
  max-width: var(--max); margin: 40px auto 0; padding-top: 24px; border-top: 1px solid #2c3034;
  color: #8b9199; font-size: 14px;
}
footer .foot-slogan b { color: var(--accent); font-weight: 600; }
footer .compliance { max-width: var(--max); margin: 16px auto 0; color: #6b7078; font-size: 12.5px; line-height: 1.8; }
@media (max-width: 820px) { footer .cols { grid-template-columns: 1fr; gap: 26px; } }

/* 内页头 */
.pagehead { padding: 70px 24px 40px; border-bottom: 1px solid var(--line); }
.pagehead h1 { font-size: clamp(30px, 4.4vw, 50px); }
.pagehead .lead { margin-top: 16px; }
.crumb { font-size: 14px; color: var(--ink-3); margin-bottom: 16px; }
.crumb a:hover { color: var(--brand); }

/* 服务详情 */
.svc { border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; margin-top: 26px; }
.svc-head { background: var(--brand); color: #fff; padding: 24px 30px; display: flex; justify-content: space-between; align-items: center; gap: 16px; flex-wrap: wrap; }
.svc-head h3 { color: #fff; font-size: 24px; }
.svc-head .price { font-size: 14px; color: var(--accent); font-weight: 700; }
.svc-body { padding: 28px 30px; }
.svc-body ul { margin: 8px 0 0 20px; color: var(--ink-2); }
.svc-body li { margin-bottom: 8px; }

/* 联系 */
.contact-card { border: 1px solid var(--line); border-radius: var(--radius); padding: 34px; }
.contact-row { display: flex; gap: 14px; padding: 16px 0; border-bottom: 1px solid var(--line); align-items: center; }
.contact-row:last-child { border-bottom: 0; }
.contact-row .k { width: 110px; color: var(--ink-3); font-size: 15px; flex: none; }
.contact-row .v { font-weight: 600; color: var(--ink); }

.note { font-size: 13.5px; color: var(--ink-3); margin-top: 12px; }

/* ============================================================
   苹果范式组件（v2 · 参照 apple.com.cn 实测提炼）
   ============================================================ */

/* 导航组合logo */
.brandmark img.brand-logo { height: 34px; width: auto; border-radius: 4px; }
@media (max-width: 620px) { .brandmark img.brand-logo { height: 28px; } }

/* —— 全屏大视觉屏（苹果式：一屏一大图+超短标题+双CTA） —— */
.screen {
  position: relative; min-height: 88vh; display: flex; align-items: flex-end;
  background-size: cover; background-position: center; color: #fff;
  padding: 0 24px 72px;
}
.screen::before {
  content: ""; position: absolute; inset: 0;
  background: linear-gradient(180deg, rgba(10,12,16,.10) 30%, rgba(10,12,16,.78) 100%);
}
.screen .wrap { position: relative; z-index: 2; width: 100%; max-width: var(--max); margin: 0 auto; }
.screen h2 { color: #fff; font-size: clamp(30px, 4.6vw, 54px); }
.screen .s-lead { margin-top: 12px; font-size: clamp(16px, 1.5vw, 20px); color: rgba(255,255,255,.92); max-width: 720px; }
.screen .concl-line { margin-top: 14px; font-size: 14.5px; color: var(--accent); font-weight: 600; }

/* —— 苹果式双CTA：灰字链接 + 胶囊按钮 —— */
.cta-duo { display: flex; gap: 26px; align-items: center; margin-top: 26px; flex-wrap: wrap; }
.cta-duo .more { color: #9aa3ab; font-weight: 600; font-size: 16px; }
.cta-duo .more::after { content: " ›"; }
.cta-duo .more:hover { color: var(--brand); text-decoration: underline; }
.cta-duo .pill {
  background: var(--brand); color: #fff; padding: 12px 28px; border-radius: 999px;
  font-weight: 700; font-size: 16px;
}
.cta-duo .pill:hover { background: var(--brand-deep); }
.screen .cta-duo .more { color: rgba(255,255,255,.75); }
.screen .cta-duo .more:hover { color: var(--accent); }
.screen .cta-duo .pill { background: #fff; color: var(--brand); }
.screen .cta-duo .pill:hover { background: var(--accent); color: var(--brand); }

/* —— 服务页置顶sticky子导航 —— */
.subnav {
  position: sticky; top: 61px; z-index: 90;
  background: rgba(255,255,255,.92); backdrop-filter: blur(18px);
  border-bottom: 1px solid var(--line);
}
.subnav-inner {
  max-width: var(--max); margin: 0 auto; padding: 12px 24px;
  display: flex; gap: 28px; align-items: center; overflow-x: auto; white-space: nowrap;
}
.subnav-inner a { font-size: 14.5px; color: var(--ink-2); font-weight: 600; }
.subnav-inner a:hover { color: var(--brand); }
.subnav-inner .sn-cta { margin-left: auto; color: var(--brand); }

/* —— 服务卖点分屏（每屏标题4-6字+两短句） —— */
.svc-screen { display: grid; grid-template-columns: 1fr 1fr; gap: 0; min-height: 72vh; align-items: stretch; }
.svc-screen .svc-img { background-size: cover; background-position: center; min-height: 340px; }
.svc-screen .svc-txt { display: flex; flex-direction: column; justify-content: center; padding: 60px 56px; }
.svc-screen .svc-txt .eyebrow { margin-bottom: 12px; }
.svc-screen .svc-txt h2 { font-size: clamp(26px, 3.2vw, 42px); }
.svc-screen .svc-txt p.s1 { margin-top: 18px; font-size: 18px; color: var(--ink); font-weight: 600; }
.svc-screen .svc-txt p.s2 { margin-top: 6px; font-size: 16px; color: var(--ink-2); max-width: 520px; }
.svc-screen.flip { direction: rtl; }
.svc-screen.flip > * { direction: ltr; }
@media (max-width: 860px) {
  .svc-screen { grid-template-columns: 1fr; }
  .svc-screen .svc-txt { padding: 40px 24px; }
  .screen { min-height: 70vh; }
}

/* —— 六宫格服务承诺 —— */
.promise-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; margin-top: 40px; }
.promise-grid .p-cell {
  border: 1px solid var(--line); border-radius: 14px; padding: 24px 22px; background: #fff;
}
.promise-grid .p-cell .p-ico { font-size: 22px; }
.promise-grid .p-cell h3 { font-size: 17px; margin: 10px 0 6px; }
.promise-grid .p-cell p { font-size: 14px; color: var(--ink-2); }
@media (max-width: 860px) { .promise-grid { grid-template-columns: 1fr 1fr; } }
@media (max-width: 560px) { .promise-grid { grid-template-columns: 1fr; } }

/* Hero v2（形象照大视觉） */
.hero-v2 {
  position: relative; min-height: 92vh; display: flex; align-items: flex-end;
  background: #101318 url("images/portrait.jpg") no-repeat right center / cover;
  color: #fff; padding: 0 24px 76px;
}
.hero-v2::before {
  content: ""; position: absolute; inset: 0;
  background: linear-gradient(90deg, rgba(10,12,16,.88) 0%, rgba(10,12,16,.55) 46%, rgba(10,12,16,.15) 100%),
              linear-gradient(0deg, rgba(10,12,16,.85) 0%, transparent 55%);
}
.hero-v2 .wrap { position: relative; z-index: 2; width: 100%; max-width: var(--max); margin: 0 auto; }
.hero-v2 .tag { display: inline-block; border: 1px solid rgba(255,255,255,.45); padding: 7px 18px; border-radius: 999px; font-size: 14px; letter-spacing: 2px; margin-bottom: 22px; }
.hero-v2 h1 { color: #fff; font-size: clamp(34px, 5vw, 60px); }
.hero-v2 .hero-sub { margin-top: 16px; font-size: clamp(16px, 1.7vw, 22px); color: #FFE9C8; font-weight: 600; max-width: 700px; }
.hero-v2 .hero-sub .hl { color: var(--accent); }
.hero-v2 .meta { margin-top: 28px; display: flex; gap: 26px; flex-wrap: wrap; color: rgba(255,255,255,.85); font-size: 14.5px; }
.hero-v2 .meta b { color: var(--accent); font-size: 20px; display: block; }
@media (max-width: 720px) {
  .hero-v2 { background-position: 72% top; }
}

/* ============================================================
   文章板块（观点）
   ============================================================ */
.article-wrap { max-width: 780px; margin: 0 auto; padding: 56px 24px 70px; }
.article-wrap .crumb { margin-bottom: 8px; }
.article-wrap h1 { font-size: clamp(26px, 3.4vw, 40px); margin: 10px 0 12px; }
.article-meta { color: var(--ink-3); font-size: 14px; margin-bottom: 34px; }
.article-body p { margin: 0 0 20px; font-size: 17px; line-height: 1.9; color: var(--ink); }
.article-body h3 { margin: 38px 0 14px; font-size: 21px; color: var(--brand-deep); }
.article-body .src-note { font-size: 13.5px; color: var(--ink-3); border-top: 1px dashed var(--line); padding-top: 16px; margin-top: 34px; }
.art-nav { display: flex; justify-content: space-between; gap: 16px; margin-top: 40px; font-size: 15px; }
.art-nav a { color: var(--brand); font-weight: 600; }

.art-tools { max-width: 780px; margin: 30px auto 0; padding: 0 24px; }
.art-tools input { width: 100%; padding: 13px 20px; border: 1px solid var(--line); border-radius: 999px; font-size: 15px; outline: none; }
.art-tools input:focus { border-color: var(--brand); }
.art-list { max-width: 780px; margin: 20px auto 0; padding: 0 24px; }
.art-item { display: block; padding: 22px 6px; border-bottom: 1px solid var(--line); }
.art-item .a-no { font-size: 12.5px; color: var(--brand); font-weight: 700; letter-spacing: 1px; }
.art-item h3 { font-size: 18px; margin: 6px 0; color: var(--ink); }
.art-item p { font-size: 14.5px; color: var(--ink-2); margin: 4px 0 6px; }
.art-item .a-date { font-size: 12.5px; color: var(--ink-3); }
.art-item:hover h3 { color: var(--brand); }
.art-count { max-width: 780px; margin: 14px auto 0; padding: 0 24px; font-size: 13.5px; color: var(--ink-3); }

/* —— 方法论图屏（图完整露出，不做背景裁切） —— */
.diagram-screen { background:#0D1320; color:#fff; text-align:center; padding:80px 24px 70px; }
.diagram-screen h2 { color:#fff; }
.diagram-screen .d-lead { color:rgba(255,255,255,.85); margin-top:12px; font-size:clamp(16px,1.5vw,20px); }
.diagram-screen img.d-fig { width:min(560px,94%); margin:28px auto 10px; border-radius:16px; display:block; box-shadow:0 20px 60px rgba(0,0,0,.45); }
.diagram-screen .concl-line { color:var(--accent); font-weight:600; font-size:14.5px; }
.diagram-screen .cta-duo { justify-content:center; }