/* ============================================================
   麦糟奇旅 · 啤酒麦糟无糖饼干科普网站
   主题：健康烘焙 · 琥珀焦糖暖色调
   ============================================================ */

:root {
  --primary: #a4682a;        /* 焦糖棕 */
  --primary-dark: #7c4a1e;
  --primary-light: #e8b45a;  /* 麦芽金 */
  --brown: #3f2d20;          /* 深棕文字 */
  --brown-soft: #7c5b3a;
  --cream: #faf5ec;          /* 米色背景 */
  --card: #fffdf8;
  --line: #eadfc9;
  --green: #7a9a4e;          /* 健康绿 */
  --teal: #3e8f8a;           /* 科学青 */
  --purple: #7a6ba8;         /* AI 紫 */
  --red: #c0605a;
  --radius: 18px;
  --shadow: 0 10px 30px rgba(94, 63, 22, 0.10);
  --shadow-lg: 0 18px 48px rgba(94, 63, 22, 0.16);
  --maxw: 1120px;
  --ease: cubic-bezier(.22, .8, .35, 1);
}

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

html { scroll-behavior: smooth; scroll-padding-top: 84px; }

body {
  /* 跨平台字体栈：macOS/iOS、Windows、Android、Linux 各得其所 */
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Source Han Sans SC",
    "Noto Sans SC", "Helvetica Neue", Arial, sans-serif;
  background: var(--cream);
  color: var(--brown);
  line-height: 1.8;
  overflow-x: hidden;
  overflow-wrap: break-word;
  -webkit-text-size-adjust: 100%;
  text-size-adjust: 100%;
  -webkit-tap-highlight-color: transparent;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img { max-width: 100%; height: auto; display: block; }
a { color: var(--primary); text-decoration: none; }
strong, b { color: var(--primary-dark); }

.container { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }
.container-narrow { max-width: 860px; }

/* ================= 滚动浮现动画 ================= */
[data-reveal] {
  opacity: 0;
  transform: translateY(28px);
  transition: opacity .7s var(--ease), transform .7s var(--ease);
}
[data-reveal].revealed { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  [data-reveal] { opacity: 1; transform: none; transition: none; }
}

/* ================= 导航 ================= */
.navbar {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  background: rgba(250, 245, 236, 0.86);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid transparent;
  transition: box-shadow .3s, border-color .3s, background .3s;
}
.navbar.scrolled { border-color: var(--line); box-shadow: 0 6px 24px rgba(94, 63, 22, .08); }

/* 不支持 backdrop-filter 的浏览器（老版 Firefox/IE 等）：改用高不透明度背景 */
@supports not ((backdrop-filter: blur(1px)) or (-webkit-backdrop-filter: blur(1px))) {
  .navbar { background: rgba(250, 245, 236, 0.97); }
  .nav-links { background: rgba(250, 245, 236, 0.99); }
}
.nav-inner {
  max-width: var(--maxw); margin: 0 auto; padding: 12px 24px;
  padding-left: calc(24px + env(safe-area-inset-left, 0px));
  padding-right: calc(24px + env(safe-area-inset-right, 0px));
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 1.15rem; color: var(--brown); min-width: 0; }
.brand-icon { font-size: 1.5rem; filter: drop-shadow(0 2px 3px rgba(0,0,0,.15)); flex-shrink: 0; }
.brand-text { overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.brand-text em { font-style: normal; color: var(--primary); }
.nav-links { display: flex; gap: 4px; flex-wrap: wrap; }
.nav-links a {
  padding: 8px 13px; border-radius: 999px; font-size: .92rem; color: var(--brown-soft);
  transition: color .25s, background .25s;
}
.nav-links a:hover { color: var(--primary-dark); background: rgba(164, 104, 42, .09); }
.nav-links a.active { color: #fff; background: var(--primary); box-shadow: 0 4px 12px rgba(164, 104, 42, .35); }

.nav-toggle {
  display: none; flex-direction: column; gap: 5px; flex-shrink: 0;
  background: none; border: 0; cursor: pointer; padding: 8px;
}
.nav-toggle span {
  width: 24px; height: 2.5px; background: var(--brown); border-radius: 2px;
  transition: transform .3s var(--ease), opacity .3s;
}
.nav-toggle.open span:nth-child(1) { transform: translateY(7.5px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-7.5px) rotate(-45deg); }

/* ================= 首屏 ================= */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex; align-items: center;
  padding: 120px 0 80px;
  background:
    radial-gradient(1100px 500px at 85% -10%, rgba(232, 180, 90, .30), transparent 60%),
    radial-gradient(900px 500px at -10% 110%, rgba(122, 154, 78, .18), transparent 60%),
    linear-gradient(180deg, #f7efdf 0%, var(--cream) 100%);
  overflow: hidden;
}
/* iOS Safari 地址栏收起后 100vh 偏大，用 svh 修正 */
@supports (min-height: 100svh) {
  .hero { min-height: 100svh; }
}
.hero-bg {
  position: absolute; inset: 0; pointer-events: none;
  background-image:
    radial-gradient(rgba(164, 104, 42, .10) 1.5px, transparent 1.5px);
  background-size: 26px 26px;
  mask-image: radial-gradient(1200px 700px at 60% 30%, #000 30%, transparent 75%);
  -webkit-mask-image: radial-gradient(1200px 700px at 60% 30%, #000 30%, transparent 75%);
}
.hero-inner {
  position: relative; max-width: var(--maxw); margin: 0 auto; padding: 0 24px;
  display: grid; grid-template-columns: 1.1fr .9fr; gap: 56px; align-items: center;
}
.hero-eyebrow {
  display: inline-block; padding: 6px 16px; margin-bottom: 22px;
  background: rgba(164, 104, 42, .12); color: var(--primary-dark);
  border: 1px solid rgba(164, 104, 42, .25);
  border-radius: 999px; font-size: .85rem; letter-spacing: 2px;
}
.hero-title { font-size: clamp(2.1rem, 4.6vw, 3.4rem); line-height: 1.25; font-weight: 800; }
.hero-accent {
  background: linear-gradient(100deg, var(--primary), #d99a3d 60%, var(--green));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero-sub { margin: 24px 0 32px; font-size: 1.06rem; color: #5d4a35; max-width: 34em; }
.hero-actions { display: flex; gap: 14px; flex-wrap: wrap; }

.btn {
  display: inline-block; padding: 12px 26px; border-radius: 999px;
  font-size: .98rem; font-weight: 600; cursor: pointer; border: 2px solid transparent;
  transition: transform .25s var(--ease), box-shadow .25s, background .25s, color .25s;
}
.btn-primary {
  background: linear-gradient(120deg, var(--primary), #c07f37);
  color: #fff; box-shadow: 0 8px 22px rgba(164, 104, 42, .35);
}
.btn-primary:hover { transform: translateY(-3px); box-shadow: 0 14px 30px rgba(164, 104, 42, .42); color: #fff; }
.btn-ghost { border-color: rgba(164, 104, 42, .4); color: var(--primary-dark); background: transparent; }
.btn-ghost:hover { background: rgba(164, 104, 42, .08); transform: translateY(-3px); }

.hero-stats {
  list-style: none; display: grid; grid-template-columns: repeat(2, 1fr);
  gap: 14px 22px; margin-top: 44px; max-width: 34em;
}
.hero-stats li {
  background: rgba(255, 253, 248, .8); border: 1px solid var(--line);
  border-radius: 14px; padding: 12px 16px;
}
.hero-stats b { display: block; font-size: 1.5rem; color: var(--primary); font-variant-numeric: tabular-nums; }
.hero-stats span { font-size: .8rem; color: var(--brown-soft); }

.hero-figure { position: relative; }
.hero-figure img {
  border-radius: 24px; box-shadow: var(--shadow-lg);
  border: 6px solid #fff; transform: rotate(1.5deg);
  transition: transform .5s var(--ease);
}
.hero-figure:hover img { transform: rotate(0deg) scale(1.015); }
.hero-figure figcaption {
  margin-top: 14px; text-align: center; font-size: .85rem; color: var(--brown-soft);
}

.scroll-hint {
  position: absolute; left: 50%; bottom: 18px; transform: translateX(-50%);
  width: 42px; height: 42px; border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  border: 1.5px solid rgba(164, 104, 42, .45); color: var(--primary-dark);
  font-size: 1.2rem; animation: bob 2s infinite;
}
@keyframes bob { 0%,100% { transform: translate(-50%, 0); } 50% { transform: translate(-50%, 8px); } }

/* ================= 章节通用 ================= */
.section { padding: 96px 0; }
.section-alt { background: linear-gradient(180deg, #f4ecdc, var(--cream)); }
.section-tag {
  display: inline-block; margin-bottom: 12px;
  color: var(--primary); font-weight: 700; letter-spacing: 3px; font-size: .85rem;
}
.section-tag::before { content: "— "; }
.section-tag::after { content: " —"; }
.section-title { font-size: clamp(1.7rem, 3.4vw, 2.4rem); font-weight: 800; line-height: 1.3; margin-bottom: 18px; }
.section-lead { max-width: 46em; font-size: 1.02rem; color: #5d4a35; margin-bottom: 48px; }

/* ================= 卡片 ================= */
.grid-2 { display: grid; grid-template-columns: 1fr 1fr; gap: 24px; }
.card {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 28px 30px; box-shadow: var(--shadow);
}
.card-title { font-size: 1.15rem; margin-bottom: 14px; }
.card p + p { margin-top: 10px; }
.card-punch {
  padding: 10px 14px; border-left: 4px solid var(--primary-light);
  background: rgba(232, 180, 90, .12); border-radius: 0 10px 10px 0;
}
.card-warm { border-top: 4px solid var(--primary-light); }
.card-green { border-top: 4px solid var(--green); }
.card-teal { border-top: 4px solid var(--teal); }
.card-purple { border-top: 4px solid var(--purple); }

.fact-list { list-style: none; }
.fact-list li { padding: 10px 0; border-bottom: 1px dashed var(--line); font-size: .96rem; }
.fact-list li:last-child { border-bottom: 0; }
.fact-list b { color: var(--primary-dark); font-size: 1.05rem; margin-right: 2px; }

/* ================= 酿造流程 ================= */
.brew-flow {
  display: flex; align-items: stretch; justify-content: center; gap: 10px;
  margin: 48px 0; flex-wrap: wrap;
}
.flow-step {
  flex: 1 1 150px; max-width: 220px; text-align: center;
  background: var(--card); border: 1px solid var(--line); border-radius: 16px;
  padding: 20px 14px; box-shadow: var(--shadow);
}
.flow-emoji { font-size: 2rem; display: block; margin-bottom: 8px; }
.flow-step h4 { font-size: 1rem; margin-bottom: 4px; }
.flow-step p { font-size: .82rem; color: var(--brown-soft); }
.flow-step-star {
  border: 2px solid var(--primary-light);
  background: linear-gradient(160deg, #fff, #fdf3e0);
  animation: glow 2.6s infinite;
}
@keyframes glow {
  0%,100% { box-shadow: 0 0 0 rgba(232, 180, 90, 0); }
  50% { box-shadow: 0 0 26px rgba(232, 180, 90, .55); }
}
.flow-arrow {
  align-self: center; font-size: 1.5rem; color: var(--primary);
  font-weight: 700; padding: 0 2px;
}
.flow-arrow-split { color: var(--green); }

/* ================= 双栏横带 ================= */
.split-band {
  display: grid; grid-template-columns: 1.15fr .85fr; gap: 30px;
  margin-top: 48px; background: var(--card); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 30px; box-shadow: var(--shadow);
}
.split-band-text h3 { margin-bottom: 12px; font-size: 1.15rem; }
.split-band-text p + p { margin-top: 10px; }
.split-band-chart { display: flex; align-items: center; justify-content: center; min-height: 260px; }
.split-band-chart canvas { width: 100%; max-width: 420px; }

/* ================= 营养宝库 ================= */
.nutrition-layout { display: grid; grid-template-columns: 1.05fr .95fr; gap: 28px; align-items: start; }
.chart-box {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 24px; box-shadow: var(--shadow); position: sticky; top: 96px;
}
.chart-title { font-size: 1rem; margin-bottom: 16px; color: var(--primary-dark); }
.chart-note { font-size: .78rem; color: #a08a6c; margin-top: 10px; }
#nutritionChart { width: 100%; }
.nutrition-cards { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; }
.mini-card {
  background: var(--card); border: 1px solid var(--line); border-radius: 16px;
  padding: 20px; box-shadow: var(--shadow); transition: transform .3s var(--ease), box-shadow .3s;
}
.mini-card:hover { transform: translateY(-5px); box-shadow: var(--shadow-lg); }
.mini-emoji { font-size: 1.7rem; display: inline-block; margin-bottom: 8px; }
.mini-card h4 { font-size: .98rem; margin-bottom: 8px; color: var(--primary-dark); }
.mini-card p { font-size: .88rem; color: #5d4a35; }

/* ================= 机制四重奏 ================= */
.mech-tabs { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); box-shadow: var(--shadow); overflow: hidden; }
.mech-tab-list { display: grid; grid-template-columns: repeat(4, 1fr); }
.mech-tab {
  padding: 16px 8px; background: #f4ead6; border: none; border-right: 1px solid var(--line);
  font-size: .95rem; font-weight: 700; color: var(--brown-soft); cursor: pointer;
  transition: background .25s, color .25s; line-height: 1.4;
}
.mech-tab:last-child { border-right: none; }
.mech-tab small { font-weight: 500; font-size: .8em; }
.mech-tab:hover { background: #efdfc2; }
.mech-tab.is-active { background: linear-gradient(140deg, var(--primary), #bd7c34); color: #fff; }
.mech-panel { display: none; padding: 30px 32px; animation: fadeIn .45s var(--ease); }
.mech-panel.is-active { display: block; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: none; } }
.mech-panel-grid { display: grid; grid-template-columns: 1.15fr .85fr; gap: 28px; align-items: center; }
.mech-panel h3 { font-size: 1.2rem; margin-bottom: 12px; color: var(--primary-dark); }
.mech-panel p + p { margin-top: 10px; }
.mech-visual { background: #fbf6ea; border: 1px dashed var(--line); border-radius: 16px; padding: 14px; }
.mech-visual canvas { width: 100%; }
.mech-visual-svg svg { width: 100%; height: auto; }

/* 证据带 */
.evidence-band { margin-top: 48px; background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 30px; box-shadow: var(--shadow); }
.evidence-band h3 { margin-bottom: 20px; }
.evidence-track { display: grid; grid-template-columns: repeat(4, 1fr); gap: 12px; margin-bottom: 18px; }
.evidence-step {
  border-radius: 14px; padding: 14px; text-align: center; border: 1.5px solid var(--line); background: #fbf6ea;
}
.evidence-step b { display: block; font-size: .98rem; margin-bottom: 4px; }
.evidence-step span { font-size: .78rem; color: var(--brown-soft); }
.evidence-step.done { border-color: rgba(122, 154, 78, .6); background: #f2f6e8; }
.evidence-step.done b { color: var(--green); }
.evidence-step.doing { border-color: rgba(232, 180, 90, .8); background: #fdf3dd; }
.evidence-step.doing b { color: #b57e17; }
.evidence-step.todo { opacity: .75; }
.evidence-step.todo b { color: #9a8b74; }
.evidence-note { font-size: .92rem; color: #5d4a35; }

/* ================= 时间线 ================= */
.timeline { list-style: none; position: relative; padding-left: 66px; }
.timeline::before {
  content: ""; position: absolute; left: 24px; top: 8px; bottom: 8px; width: 3px;
  background: linear-gradient(180deg, var(--primary-light), var(--primary), var(--green));
  border-radius: 3px;
}
.tl-item { position: relative; margin-bottom: 40px; }
.tl-item:last-child { margin-bottom: 0; }
.tl-marker {
  position: absolute; left: -66px; top: 0;
  width: 48px; height: 48px; border-radius: 50%;
  background: linear-gradient(140deg, var(--primary), #c07f37); color: #fff;
  display: flex; align-items: center; justify-content: center;
  font-weight: 800; font-size: 1.15rem;
  box-shadow: 0 6px 16px rgba(164, 104, 42, .35); border: 4px solid var(--cream);
}
.tl-body {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 24px 28px; box-shadow: var(--shadow);
  transition: transform .3s var(--ease);
}
.tl-body:hover { transform: translateX(6px); }
.tl-body h3 { font-size: 1.12rem; color: var(--primary-dark); margin-bottom: 6px; }
.tl-meta { display: inline-block; font-size: .8rem; color: var(--teal); background: rgba(62, 143, 138, .1); border-radius: 999px; padding: 3px 12px; margin-bottom: 10px; }
.tl-body p { font-size: .95rem; color: #5d4a35; }

/* ================= AI 章节 ================= */
.ai-net-wrap {
  margin: 40px 0; background: var(--card); border: 1px solid var(--line);
  border-radius: var(--radius); padding: 26px; box-shadow: var(--shadow);
  text-align: center;
}
#bpNetSvg { width: 100%; max-width: 640px; height: auto; }
#bpNetSvg .bp-edge { stroke: #d9c5a5; stroke-width: 1; }
#bpNetSvg .bp-edge.pulse { stroke: var(--primary); stroke-width: 1.8; animation: edgeGlow 1.4s infinite; }
@keyframes edgeGlow { 0%,100% { opacity: .35; } 50% { opacity: 1; } }
#bpNetSvg .bp-node { fill: #fff; stroke: var(--primary); stroke-width: 2; }
#bpNetSvg .bp-node-out { stroke: var(--teal); fill: #e9f4f3; }
#bpNetSvg .bp-label { font-size: 12px; fill: var(--brown-soft); }
#bpNetSvg .bp-val { font-size: 13px; font-weight: 700; fill: var(--primary-dark); }

.score-band {
  display: grid; grid-template-columns: .8fr 1.2fr; gap: 28px; align-items: center;
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 28px; box-shadow: var(--shadow); margin-bottom: 40px;
}
.score-band-chart { display: flex; justify-content: center; }
.score-band-chart canvas { width: 100%; max-width: 300px; }
.score-band-text h3 { margin-bottom: 12px; }

/* ================= 配方实验室 ================= */
.lab {
  background: linear-gradient(160deg, #33261b, #4a3524 60%, #3d2b1f);
  border-radius: 24px; padding: 36px 34px; color: #f2e7d5;
  box-shadow: var(--shadow-lg);
}
.lab-title { font-size: 1.4rem; margin-bottom: 8px; color: #ffe9c4; }
.lab-sub { font-size: .92rem; color: #d8c4a5; margin-bottom: 26px; max-width: 46em; }
.lab-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 30px; }
.lab-slider { display: block; margin-bottom: 22px; }
.lab-slider-head { display: flex; justify-content: space-between; margin-bottom: 8px; font-size: .95rem; }
.lab-slider-head output { color: var(--primary-light); font-weight: 700; font-variant-numeric: tabular-nums; }
.lab-slider input[type="range"] {
  width: 100%; height: 6px; appearance: none; -webkit-appearance: none;
  background: linear-gradient(90deg, var(--primary-light), #8a6a3f);
  border-radius: 6px; outline: none; cursor: pointer;
}
.lab-slider input[type="range"]::-webkit-slider-thumb {
  appearance: none; -webkit-appearance: none;
  width: 22px; height: 22px; border-radius: 50%;
  background: radial-gradient(circle at 35% 35%, #ffe9c4, var(--primary-light));
  border: 2px solid #fff3; box-shadow: 0 3px 10px rgba(0, 0, 0, .4);
  transition: transform .2s;
}
.lab-slider input[type="range"]::-webkit-slider-thumb:hover { transform: scale(1.15); }
.lab-slider input[type="range"]::-moz-range-thumb {
  width: 20px; height: 20px; border-radius: 50%;
  background: var(--primary-light); border: 2px solid #fff3; cursor: pointer;
}
.lab-buttons { display: flex; gap: 12px; flex-wrap: wrap; margin-top: 6px; }
.lab .btn-primary { background: linear-gradient(120deg, var(--primary-light), #d99a3d); color: #33261b; box-shadow: 0 8px 20px rgba(0, 0, 0, .3); }
.lab .btn-primary:hover { color: #33261b; }
.lab .btn-ghost { border-color: rgba(232, 180, 90, .5); color: #ffe9c4; }
.lab .btn-ghost:hover { background: rgba(232, 180, 90, .12); color: #ffe9c4; }
.lab-hint { margin-top: 16px; font-size: .82rem; color: #c4ad8b; }

.lab-results { display: flex; flex-direction: column; gap: 16px; }
.lab-gauge { align-self: center; width: 100%; max-width: 260px; }
.lab-gauge svg { width: 100%; height: auto; }
.lab-bars { display: flex; flex-direction: column; gap: 10px; }
.lab-bar-row {
  display: grid; grid-template-columns: 110px 1fr 64px; align-items: center; gap: 10px;
  font-size: .85rem;
}
.lab-bar { height: 12px; background: rgba(255, 255, 255, .12); border-radius: 8px; overflow: hidden; }
.lab-bar i {
  display: block; height: 100%; width: 0;
  background: linear-gradient(90deg, var(--primary-light), #ffd98a);
  border-radius: 8px; transition: width .5s var(--ease);
}
.lab-bar-rev .lab-bar i { background: linear-gradient(90deg, #6fae6f, #a9d18e); }
.lab-bar-row output { text-align: right; font-variant-numeric: tabular-nums; color: #ffe9c4; font-weight: 700; }
.lab-verdict {
  font-size: .9rem; color: #f2e7d5; background: rgba(255, 255, 255, .07);
  border-left: 4px solid var(--primary-light); border-radius: 0 10px 10px 0; padding: 10px 14px;
  min-height: 3.2em;
}

/* ================= 产品 ================= */
.product-layout { display: grid; grid-template-columns: .9fr 1.1fr; gap: 36px; align-items: start; margin-bottom: 56px; }
.product-figure { position: sticky; top: 96px; }
.product-figure img {
  border-radius: 22px; border: 6px solid #fff; box-shadow: var(--shadow-lg);
  transform: rotate(-1.5deg); transition: transform .5s var(--ease);
}
.product-figure:hover img { transform: rotate(0); }
.product-figure figcaption { margin-top: 12px; text-align: center; font-size: .85rem; color: var(--brown-soft); }
.feature-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.feature {
  background: var(--card); border: 1px solid var(--line); border-radius: 16px;
  padding: 18px 20px; box-shadow: var(--shadow); transition: transform .3s var(--ease);
}
.feature:hover { transform: translateY(-4px); }
.feature span { font-size: 1.5rem; }
.feature h4 { font-size: .98rem; margin: 6px 0; color: var(--primary-dark); }
.feature p { font-size: .85rem; color: #5d4a35; }
.result-band {
  margin-top: 22px; background: linear-gradient(140deg, #f2f6e8, #eaf2df);
  border: 1px solid rgba(122, 154, 78, .4); border-radius: 16px; padding: 20px 24px;
}
.result-band h4 { color: var(--green); margin-bottom: 8px; }
.result-band p { font-size: .92rem; color: #4a5a3a; }

.future-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.future-card {
  background: var(--card); border: 1px solid var(--line); border-radius: 16px;
  padding: 22px; box-shadow: var(--shadow); transition: transform .3s var(--ease);
}
.future-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-lg); }
.future-emoji { font-size: 1.8rem; display: inline-block; margin-bottom: 10px; }
.future-card h4 { font-size: 1rem; margin-bottom: 8px; color: var(--primary-dark); }
.future-card p { font-size: .86rem; color: #5d4a35; }

/* ================= FAQ ================= */
.faq-list { display: flex; flex-direction: column; gap: 14px; }
.faq-item {
  background: var(--card); border: 1px solid var(--line); border-radius: 16px;
  box-shadow: var(--shadow); overflow: hidden; transition: border-color .3s;
}
.faq-item[open] { border-color: rgba(164, 104, 42, .45); }
.faq-item summary {
  list-style: none; cursor: pointer; padding: 18px 56px 18px 22px;
  font-weight: 700; font-size: 1rem; position: relative; user-select: none;
}
.faq-item summary::-webkit-details-marker { display: none; }
.faq-plus {
  position: absolute; right: 18px; top: 50%; transform: translateY(-50%);
  width: 26px; height: 26px; border-radius: 50%;
  background: rgba(164, 104, 42, .12); transition: transform .35s var(--ease), background .35s;
}
.faq-plus::before, .faq-plus::after {
  content: ""; position: absolute; left: 50%; top: 50%;
  width: 12px; height: 2px; background: var(--primary-dark);
  transform: translate(-50%, -50%); border-radius: 2px; transition: transform .35s var(--ease);
}
.faq-plus::after { transform: translate(-50%, -50%) rotate(90deg); }
.faq-item[open] .faq-plus { background: var(--primary); }
.faq-item[open] .faq-plus::before,
.faq-item[open] .faq-plus::after { background: #fff; }
.faq-item[open] .faq-plus::after { transform: translate(-50%, -50%) rotate(0deg); }
.faq-body { padding: 0 22px 20px; animation: fadeIn .4s var(--ease); }
.faq-body p { font-size: .94rem; color: #5d4a35; }

/* ================= 页脚 ================= */
.footer {
  background: linear-gradient(160deg, #33261b, #453322);
  color: #d8c4a5; padding: 56px 0 28px; margin-top: 40px;
}
.footer-grid { display: grid; grid-template-columns: 1.4fr 1fr 1fr 1.4fr; gap: 30px; padding-bottom: 30px; border-bottom: 1px solid rgba(255, 255, 255, .1); }
.footer .brand { color: #ffe9c4; margin-bottom: 12px; }
.footer .brand-text em { color: var(--primary-light); }
.footer-brand p { font-size: .88rem; }
.footer-col h5 { color: #ffe9c4; margin-bottom: 12px; font-size: .95rem; }
.footer-col a { display: block; color: #d8c4a5; font-size: .88rem; padding: 4px 0; transition: color .25s, transform .25s; }
.footer-col a:hover { color: #ffd98a; transform: translateX(4px); }
.footer-disclaimer p { font-size: .8rem; color: #b09b7c; }
.footer-copy { text-align: center; font-size: .8rem; color: #b09b7c; padding-top: 24px; }

/* ================= 返回顶部 ================= */
.back-top {
  position: fixed; right: 26px; bottom: 30px; z-index: 90;
  right: calc(26px + env(safe-area-inset-right, 0px));
  bottom: calc(30px + env(safe-area-inset-bottom, 0px));
  width: 46px; height: 46px; border-radius: 50%; border: none;
  background: linear-gradient(140deg, var(--primary), #c07f37); color: #fff;
  font-size: 1.2rem; cursor: pointer; box-shadow: 0 8px 22px rgba(164, 104, 42, .4);
  opacity: 0; visibility: hidden; transform: translateY(16px);
  transition: opacity .35s, transform .35s, visibility .35s;
}
.back-top.show { opacity: 1; visibility: visible; transform: none; }
.back-top:hover { transform: translateY(-4px); }

/* ================= 响应式 ================= */
@media (max-width: 980px) {
  .hero-inner { grid-template-columns: 1fr; gap: 40px; }
  .hero-figure { max-width: 560px; }
  .hero { padding-top: 110px; }
  .grid-2, .nutrition-layout, .mech-panel-grid, .split-band,
  .score-band, .lab-grid, .product-layout { grid-template-columns: 1fr; }
  .chart-box { position: static; }
  .product-figure { position: static; max-width: 480px; margin: 0 auto; }
  .future-grid { grid-template-columns: 1fr 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .evidence-track { grid-template-columns: 1fr 1fr; }
}

@media (max-width: 760px) {
  .nav-toggle { display: flex; }
  .nav-links {
    position: fixed; top: 62px; left: 0; right: 0;
    flex-direction: column; gap: 0;
    background: rgba(250, 245, 236, .98); backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--line);
    max-height: 0; overflow: hidden; transition: max-height .4s var(--ease);
  }
  .nav-links.open { max-height: 480px; box-shadow: 0 20px 40px rgba(94, 63, 22, .15); }
  .nav-links a { padding: 14px 24px; border-radius: 0; border-bottom: 1px solid rgba(234, 223, 201, .6); }
  .mech-tab-list { grid-template-columns: 1fr 1fr; }
  .mech-tab { border-bottom: 1px solid var(--line); }
  .mech-panel { padding: 22px 18px; }
  .nutrition-cards { grid-template-columns: 1fr; }
  .feature-grid { grid-template-columns: 1fr; }
  .timeline { padding-left: 54px; }
  .timeline::before { left: 18px; }
  .tl-marker { left: -54px; width: 40px; height: 40px; font-size: 1rem; }
  .section { padding: 64px 0; }
  .hero-stats { grid-template-columns: 1fr 1fr; gap: 10px 12px; }
  .lab { padding: 24px 18px; }
  .lab-bar-row { grid-template-columns: 96px 1fr 58px; }
  .split-band, .card, .evidence-band, .score-band { padding: 22px 18px; }
  .flow-step { flex: 1 1 130px; }
}

@media (max-width: 480px) {
  .future-grid, .evidence-track, .footer-grid { grid-template-columns: 1fr; }
  .hero-stats { grid-template-columns: 1fr; }
  .hero-actions .btn { width: 100%; text-align: center; }
}

/* ================= 仪表盘标注自适应 ================= */
@media (max-width: 520px) {
  .gauge-caption { font-size: 10px; }
}

/* ================= 超宽屏与大桌面 ================= */
@media (min-width: 1600px) { :root { --maxw: 1240px; } }
@media (min-width: 2000px) { :root { --maxw: 1400px; } }

/* ================= 平板竖屏（761–1024px） ================= */
@media (min-width: 761px) and (max-width: 1024px) {
  .section { padding: 80px 0; }
  .nutrition-layout { grid-template-columns: 1fr; }
  .nutrition-cards { grid-template-columns: 1fr 1fr; }
  .future-grid { grid-template-columns: 1fr 1fr; }
  .product-layout { grid-template-columns: 1fr; }
  .product-figure { position: static; max-width: 520px; margin: 0 auto; }
}

/* ================= 手机横屏 / 矮窗口 ================= */
@media (max-width: 1024px) and (max-height: 560px) and (orientation: landscape) {
  .hero { min-height: auto; padding: 96px 0 48px; }
  .hero-inner { grid-template-columns: 1.1fr .9fr; gap: 32px; }
  .hero-stats { grid-template-columns: repeat(4, 1fr); margin-top: 26px; max-width: none; }
  .hero-stats b { font-size: 1.15rem; }
  .hero-stats span { font-size: .72rem; }
  .scroll-hint { display: none; }
  .section { padding: 56px 0; }
  .section-lead { margin-bottom: 32px; }
}

/* ================= 触屏设备（无悬停） ================= */
@media (hover: none) {
  .btn { min-height: 48px; display: inline-flex; align-items: center; justify-content: center; }
  .nav-links a { padding: 12px 14px; }
  .mech-tab { min-height: 56px; }
  .faq-item summary { min-height: 56px; display: flex; align-items: center; padding-right: 58px; }
  .faq-plus { right: 16px; }
  .mini-card:hover, .feature:hover, .future-card:hover,
  .tl-body:hover, .hero-figure:hover img, .product-figure:hover img { transform: none; }
  .back-top { width: 52px; height: 52px; }
  .lab-slider input[type="range"] { height: 10px; }
  .lab-slider input[type="range"]::-webkit-slider-thumb { width: 28px; height: 28px; }
  .lab-slider input[type="range"]::-moz-range-thumb { width: 26px; height: 26px; }
}

/* ================= 小屏手机（≤400px，iPhone SE / 安卓小屏） ================= */
@media (max-width: 400px) {
  .container { padding: 0 16px; }
  .nav-inner { padding-top: 10px; padding-bottom: 10px; }
  .brand-text { font-size: 1.05rem; }
  .hero { padding: 92px 0 60px; }
  .hero-title { font-size: 1.75rem; }
  .hero-stats b { font-size: 1.25rem; }
  .section { padding: 56px 0; }
  .section-title { font-size: 1.5rem; }
  .section-lead { font-size: .95rem; margin-bottom: 32px; }
  .card { padding: 20px 18px; }
  .split-band, .evidence-band, .score-band { padding: 20px 16px; }
  .mech-panel { padding: 20px 16px; }
  .mech-panel-grid { gap: 18px; }
  .mech-tab { font-size: .84rem; }
  .tl-body { padding: 18px 16px; }
  .lab { padding: 20px 14px; border-radius: 18px; }
  .lab-bar-row { grid-template-columns: 84px 1fr 52px; font-size: .78rem; }
  .lab-slider-head { font-size: .88rem; }
  .footer-grid { gap: 22px; }
  .flow-arrow { display: none; }
  .flow-step { flex: 1 1 100%; max-width: none; }
}

/* ================= 打印友好 ================= */
@media print {
  .navbar, .back-top, .scroll-hint, .lab { display: none; }
  body { background: #fff; }
}