/* 基础主题与排版 */
:root {
  --bg: #0b0d0f;
  --text: #e9eef6;
  --muted: #9aa4b2;
  --card: #111317;
  --stroke: #1c2128;
  --accent: #32d74b; /* 绿色扫描 */
  --accent-blue: #45b2ff; /* 条码色 */
  --accent-yellow: #ffce39; /* 相册色 */
}
* { box-sizing: border-box; }
html, body { height: 100%; }
body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'PingFang SC', 'Noto Sans SC', 'Hiragino Sans GB', 'Microsoft YaHei', sans-serif;
  color: var(--text);
  background: radial-gradient(1200px 600px at 20% -10%, #18202a 0%, var(--bg) 40%) no-repeat, var(--bg);
}

/* 容器与按钮 */
.container { width: 100%; max-width: 1160px; margin: 0 auto; padding: 0 20px; }
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; padding: 12px 18px; border-radius: 12px; text-decoration: none; color: var(--text); border: 1px solid var(--stroke); background: transparent; transition: all .2s; }
.btn.small { padding: 8px 14px; border-radius: 10px; }
.btn.primary { background: linear-gradient(180deg, #3ddc84 0%, var(--accent) 100%); color: #06140a; border: none; font-weight: 600; }
.btn.ghost { background: rgba(255,255,255,0.04); }
.btn:hover { transform: translateY(-1px); }

/* 顶部导航 */
.site-header { position: sticky; top: 0; z-index: 10; backdrop-filter: saturate(140%) blur(8px); background: rgba(11,13,15,0.6); border-bottom: 1px solid var(--stroke); }
.header-inner { display: flex; align-items: center; justify-content: space-between; height: 56px; }
.brand { font-weight: 700; letter-spacing: .3px; }
.nav { display: flex; gap: 16px; align-items: center; }
.nav a { color: var(--text); text-decoration: none; }

/* Hero */
.hero { padding: 56px 0 20px; }
.hero-inner { display: grid; grid-template-columns: 1.05fr .95fr; gap: 28px; align-items: center; }
.hero-copy h1 { margin: 0 0 10px; font-size: clamp(24px, 4vw, 40px); }
.hero-copy p { margin: 8px 0 16px; color: var(--muted); line-height: 1.6; }
.hero-actions { display: flex; gap: 12px; margin: 18px 0 12px; }
.trust-points { display: grid; grid-template-columns: 1fr; gap: 8px; padding-left: 18px; color: var(--muted); }

/* 手机预览 */
.phone { width: 330px; max-width: 100%; margin: 0 auto; border-radius: 28px; background: linear-gradient(180deg, #0f1216 0%, #0a0c10 100%); border: 1px solid #0e1319; box-shadow: 0 20px 60px rgba(0,0,0,.55), inset 0 0 0 1px rgba(255,255,255,.04); position: relative; }
.phone-notch { height: 26px; border-radius: 28px 28px 0 0; background: transparent; position: relative; }
.camera-view { height: 420px; position: relative; overflow: hidden; border-radius: 24px; margin: 0 12px; background: linear-gradient(180deg, rgba(120,130,140,.25), rgba(60,70,80,.18)); }

/* 食物底图 */
.food-bg { position: absolute; inset: 0; background: url('greens.jpg') center/cover no-repeat, linear-gradient(180deg, rgba(120,130,140,.18), rgba(60,70,80,.12)); filter: saturate(1.02) contrast(1.05) brightness(.98) blur(.8px); transform: scale(1.01); }
 .food-bg::after { content: ""; position: absolute; inset: 0; background: radial-gradient(120% 70% at 50% 50%, rgba(0,0,0,0) 60%, rgba(0,0,0,.38) 100%); pointer-events: none; }
/* 扫描框与线条 */
.scan-corners .corner { position: absolute; width: 26px; height: 26px; border: 3px solid var(--accent); border-radius: 6px; }
.corner.tl { top: 70px; left: 26px; border-right: none; border-bottom: none; }
.corner.tr { top: 70px; right: 26px; border-left: none; border-bottom: none; }
.corner.bl { bottom: 70px; left: 26px; border-right: none; border-top: none; }
.corner.br { bottom: 70px; right: 26px; border-left: none; border-top: none; }
.scan-line { position: absolute; left: 32px; right: 32px; top: 200px; height: 3px; background: var(--accent); box-shadow: 0 0 14px var(--accent); animation: scanMove 3.5s ease-in-out infinite; opacity: .9; }
@keyframes scanMove { 0% { top: 130px; } 50% { top: 290px; } 100% { top: 130px; } }

.calorie-badge { position: absolute; left: 50%; transform: translateX(-50%); bottom: 95px; background: rgba(6,18,12,.8); border: 1px solid rgba(50,215,75,.35); color: #aef3c1; padding: 10px 14px; border-radius: 14px; font-weight: 600; box-shadow: 0 10px 30px rgba(0,0,0,.35); }

/* 模式切换与快门区域 */
.camera-modes { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; padding: 10px 14px; }
.mode { padding: 10px 12px; background: rgba(255,255,255,.05); border: 1px solid rgba(255,255,255,.08); color: var(--text); border-radius: 12px; font-size: 13px; }
.mode.active { background: rgba(50,215,75,.14); border-color: rgba(50,215,75,.4); }
.shutter-row { display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; padding: 6px 14px 14px; gap: 10px; }
.shutter { width: 66px; height: 66px; border-radius: 50%; border: 3px solid rgba(255,255,255,.85); background: #fff; box-shadow: 0 5px 18px rgba(0,0,0,.35); }
.mute { width: 36px; height: 36px; border-radius: 18px; border: 1px solid rgba(255,255,255,.15); background: rgba(255,255,255,.06); color: var(--muted); }

/* 功能亮点 */
.features { padding: 36px 0 12px; }
.features h2, .how h2 { margin: 0 0 14px; font-size: clamp(20px, 3.2vw, 28px); }
.feature-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
.feature-card { background: var(--card); border: 1px solid var(--stroke); border-radius: 16px; padding: 16px; }
.feature-card .icon { font-size: 22px; margin-bottom: 6px; }
.feature-card h3 { margin: 0 0 6px; font-size: 16px; }
.feature-card p { margin: 0; color: var(--muted); }

/* 使用步骤 */
.how { padding: 10px 0 24px; }
.steps { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; list-style: decimal inside; color: var(--muted); }
.steps li { background: var(--card); border: 1px solid var(--stroke); border-radius: 14px; padding: 12px; }

/* CTA */
.cta { padding: 30px 0 40px; }
.cta-inner { background: linear-gradient(180deg, rgba(61,220,132,.14), rgba(61,220,132,.08)); border: 1px solid rgba(61,220,132,.28); border-radius: 16px; padding: 20px; text-align: center; }
.cta-inner p { color: var(--muted); }
.cta-actions { display: inline-flex; gap: 12px; margin-top: 8px; }

/* 页脚 */
.site-footer { border-top: 1px solid var(--stroke); padding: 16px 0; }
.footer-inner { display: flex; justify-content: space-between; align-items: center; color: var(--muted); }
.footer-links { display: flex; gap: 12px; }
.footer-links a { color: var(--muted); text-decoration: none; }

/* 响应式 */
@media (max-width: 960px) {
  .hero-inner { grid-template-columns: 1fr; }
  .hero { padding-top: 30px; }
}
@media (max-width: 720px) {
  .feature-grid { grid-template-columns: 1fr 1fr; }
  .steps { grid-template-columns: 1fr; }
  .nav a:not(.btn) { display: none; }
}
@media (max-width: 420px) {
  .feature-grid { grid-template-columns: 1fr; }
}