/* 知我 ZhiWo 官网 — 白底极简（对齐 redesign） */

:root {
  color-scheme: light;
  --bg: #ffffff;
  --fg: #2e2e38;
  --muted: #858585;
  --muted-soft: rgba(133, 133, 133, 0.7);
  --border: #e8e8e8;
  --secondary: #f8f8f8;
  --primary: #7c3aed;
  --primary-fg: #ffffff;
  --amber: #c47a2e;
  --radius: 0.625rem;
  --font: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", "Segoe UI",
    -apple-system, sans-serif;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 5rem;
}

body {
  margin: 0;
  font-family: var(--font);
  background: var(--bg);
  color: var(--fg);
  -webkit-font-smoothing: antialiased;
  line-height: 1.5;
}

a {
  color: inherit;
  text-decoration: none;
}

h1,
h2,
h3,
p,
ul,
ol,
figure {
  margin: 0;
}

ul,
ol {
  padding: 0;
  list-style: none;
}

img {
  display: block;
  max-width: 100%;
}

/* ── layout ── */

.container {
  margin: 0 auto;
  max-width: 72rem;
  padding: 0 1.5rem;
}

.container-md {
  max-width: 64rem;
}

.container-sm {
  max-width: 42rem;
}

.section {
  padding: 5rem 1.5rem;
}

.section-border {
  border-top: 1px solid var(--border);
}

.section-head {
  margin: 0 auto 3.5rem;
  max-width: 36rem;
  text-align: center;
}

.section-head h2,
.section-title-alone,
.download-inner h2 {
  font-size: 1.875rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  text-wrap: balance;
}

.section-title-alone {
  margin-bottom: 3rem;
  text-align: center;
}

.section-head p,
.download-inner > p {
  margin-top: 0.75rem;
  color: var(--muted);
  line-height: 1.7;
}

/* ── buttons ── */

.btn {
  display: inline-block;
  border-radius: 0.375rem;
  padding: 0.75rem 1.75rem;
  font-size: 0.875rem;
  font-weight: 500;
  transition: opacity 0.15s, background 0.15s;
}

.btn-sm {
  padding: 0.5rem 1rem;
}

.btn-block {
  display: block;
  margin-top: 1rem;
  text-align: center;
}

.btn-dark {
  background: var(--fg);
  color: var(--bg);
}

.btn-dark:hover {
  opacity: 0.9;
}

.btn-outline {
  border: 1px solid var(--border);
  background: var(--bg);
  color: var(--fg);
}

.btn-outline:hover {
  background: var(--secondary);
}

/* ── header ── */

.site-header {
  position: fixed;
  inset: 0 0 auto;
  z-index: 50;
  border-bottom: 1px solid transparent;
  background: transparent;
  transition: background 0.3s, border-color 0.3s, backdrop-filter 0.3s;
}

.site-header.scrolled {
  border-bottom-color: var(--border);
  background: rgba(255, 255, 255, 0.9);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4rem;
  max-width: 72rem;
  margin: 0 auto;
  padding: 0 1.5rem;
}

.logo {
  font-size: 1.0625rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--primary);
}

.logo span {
  font-size: 0.875rem;
  font-weight: 500;
}

.nav-desktop {
  display: none;
  align-items: center;
  gap: 2rem;
}

.nav-desktop a {
  font-size: 0.875rem;
  color: var(--muted);
  transition: color 0.15s;
}

.nav-desktop a:hover {
  color: var(--fg);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.menu-toggle {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  padding: 0.5rem;
  border: 0;
  background: none;
  cursor: pointer;
}

.menu-toggle span {
  display: block;
  width: 1.25rem;
  height: 2px;
  border-radius: 1px;
  background: var(--fg);
}

.nav-mobile {
  display: flex;
  flex-direction: column;
  padding: 0 1.5rem 1rem;
  border-bottom: 1px solid var(--border);
  background: var(--bg);
}

.nav-mobile a:not(.btn) {
  padding: 0.75rem 0;
  border-bottom: 1px solid rgba(232, 232, 232, 0.6);
  font-size: 0.875rem;
  color: var(--muted);
}

.nav-mobile[hidden] {
  display: none;
}

.hide-sm {
  display: none;
}

@media (min-width: 768px) {
  .nav-desktop {
    display: flex;
  }

  .menu-toggle,
  .nav-mobile {
    display: none !important;
  }

  .hide-sm {
    display: inline-block;
  }
}

/* ── hero ── */

.hero {
  padding: 8rem 1.5rem 5rem;
}

.hero-inner {
  margin: 0 auto;
  max-width: 48rem;
  text-align: center;
}

.hero h1 {
  font-size: 2.25rem;
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.02em;
  text-wrap: balance;
}

.hero p {
  margin: 1.5rem auto 0;
  max-width: 36rem;
  color: var(--muted);
  line-height: 1.7;
  text-wrap: pretty;
}

.hero-ctas {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: center;
  gap: 0.875rem;
  margin-top: 2.25rem;
}

@media (min-width: 768px) {
  .hero {
    padding-top: 10rem;
  }

  .hero h1 {
    font-size: 3rem;
  }
}

/* ── how / steps ── */

.steps {
  display: grid;
  gap: 2.5rem;
}

.step-num {
  font-size: 0.875rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--muted);
}

.steps h3 {
  margin-top: 0.75rem;
  font-size: 1.125rem;
  font-weight: 700;
}

.steps p {
  margin-top: 0.5rem;
  font-size: 0.875rem;
  color: var(--muted);
  line-height: 1.7;
}

@media (min-width: 768px) {
  .steps {
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
  }
}

/* ── features ── */

.feature-row {
  display: grid;
  align-items: center;
  gap: 2.5rem;
  padding: 3.5rem 0;
}

.feature-tag {
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--muted);
}

.feature-copy h3 {
  margin-top: 0.75rem;
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  line-height: 1.35;
  text-wrap: balance;
}

.feature-copy > p:not(.feature-tag) {
  margin-top: 1rem;
  color: var(--muted);
  line-height: 1.7;
}

.feature-list {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin-top: 1.5rem;
}

.feature-list li {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  font-size: 0.875rem;
  color: var(--muted);
  line-height: 1.7;
}

.feature-list li::before {
  content: "";
  flex-shrink: 0;
  width: 0.375rem;
  height: 0.375rem;
  margin-top: 0.5rem;
  border-radius: 50%;
  background: var(--primary);
}

.feature-art {
  border: 1px solid var(--border);
  border-radius: 0.5rem;
  background: rgba(248, 248, 248, 0.4);
  padding: 1.75rem;
}

@media (min-width: 768px) {
  .feature-row {
    grid-template-columns: 1fr 1fr;
    gap: 4rem;
  }

  .feature-row.flip .feature-copy {
    order: 2;
  }

  .feature-row.flip .feature-art {
    order: 1;
  }

  .feature-copy h3 {
    font-size: 1.75rem;
  }

  .feature-art {
    padding: 2.25rem;
  }
}

/* radar */

.radar-art svg {
  display: block;
  width: 100%;
  max-width: 24rem;
  margin: 0 auto;
}

.radar-grid {
  stroke: var(--border);
}

.radar-a {
  fill: color-mix(in oklab, var(--primary) 15%, transparent);
  stroke: var(--primary);
  stroke-width: 2;
}

.radar-b {
  fill: color-mix(in oklab, var(--amber) 12%, transparent);
  stroke: var(--amber);
  stroke-width: 2;
}

.radar-labels {
  fill: var(--muted);
  font-size: 12px;
}

.radar-art figcaption {
  display: flex;
  justify-content: center;
  gap: 1.5rem;
  margin-top: 0.75rem;
  font-size: 0.75rem;
  color: var(--muted);
}

.radar-art figcaption b {
  color: var(--fg);
  font-weight: 700;
}

.radar-art figcaption span {
  display: flex;
  align-items: center;
  gap: 0.375rem;
}

.dot {
  display: inline-block;
  width: 0.5rem;
  height: 0.5rem;
  border-radius: 50%;
}

.dot-primary {
  background: var(--primary);
}

.dot-primary-soft {
  background: color-mix(in oklab, var(--primary) 30%, transparent);
}

.dot-amber {
  background: var(--amber);
}

/* plan art */

.plan-title {
  margin-bottom: 1.25rem;
  font-size: 0.875rem;
  font-weight: 700;
}

.plan-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.75rem;
  padding: 0.375rem 0;
  font-size: 0.875rem;
}

.plan-row.muted {
  color: var(--muted);
}

.plan-row.active {
  font-weight: 500;
}

.plan-sub {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  margin-left: 2rem;
  padding: 0.25rem 0;
  font-size: 0.8125rem;
  color: var(--muted);
}

.badge,
.badge-sm {
  display: grid;
  flex-shrink: 0;
  place-items: center;
  border-radius: 50%;
  font-size: 0.625rem;
}

.badge {
  width: 1.25rem;
  height: 1.25rem;
}

.badge-sm {
  width: 1rem;
  height: 1rem;
  border-radius: 0.25rem;
  font-size: 0.5625rem;
}

.badge-done {
  background: var(--primary);
  color: var(--primary-fg);
}

.badge-current {
  border: 1px solid var(--primary);
  color: var(--primary);
}

.badge-idle {
  border: 1px solid var(--border);
  color: var(--muted);
}

.badge-empty {
  border: 1px solid var(--border);
  background: var(--bg);
  border-radius: 0.25rem;
}

.progress {
  display: block;
  width: 100%;
  max-width: 200px;
  height: 0.375rem;
  margin-left: 2rem;
  flex-basis: 100%;
  overflow: hidden;
  border-radius: 999px;
  background: color-mix(in oklab, var(--primary) 15%, transparent);
}

.progress i {
  display: block;
  height: 100%;
  border-radius: 999px;
  background: var(--primary);
}

/* heat / chat */

.heatmap {
  display: grid;
  grid-auto-flow: column;
  grid-template-rows: repeat(7, 11px);
  grid-auto-columns: 11px;
  gap: 3px;
}

.heatmap span {
  border-radius: 3px;
}

.heat-0 {
  background: color-mix(in oklab, var(--primary) 10%, transparent);
}
.heat-1 {
  background: color-mix(in oklab, var(--primary) 30%, transparent);
}
.heat-2 {
  background: color-mix(in oklab, var(--primary) 60%, transparent);
}
.heat-3 {
  background: var(--primary);
}

.chat-bubbles {
  display: flex;
  flex-direction: column;
  gap: 0.625rem;
  margin-top: 1.25rem;
}

.bubble {
  max-width: 88%;
  padding: 0.5rem 0.875rem;
  font-size: 0.8125rem;
  line-height: 1.6;
  border-radius: 0.75rem;
}

.bubble-user {
  align-self: flex-end;
  border-bottom-right-radius: 0.25rem;
  background: var(--primary);
  color: var(--primary-fg);
}

.bubble-ai {
  align-self: flex-start;
  border-bottom-left-radius: 0.25rem;
  background: var(--bg);
  color: var(--muted);
  box-shadow: 0 0 0 1px var(--border);
}

/* notify */

.notify-art {
  display: flex;
  flex-direction: column;
  gap: 0.875rem;
}

.notify-card {
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  padding: 1rem;
  border: 1px solid var(--border);
  border-radius: 0.5rem;
  background: var(--bg);
}

.notify-card .dot {
  margin-top: 0.375rem;
  flex-shrink: 0;
}

.notify-card.faded {
  opacity: 0.7;
}

.notify-title {
  font-size: 0.875rem;
  font-weight: 700;
}

.notify-card p:not(.notify-title) {
  margin-top: 0.25rem;
  font-size: 0.8125rem;
  color: var(--muted);
  line-height: 1.6;
}

/* ── tech ── */

.tech-grid {
  display: grid;
  gap: 2.5rem 3rem;
}

.tech-grid article {
  display: flex;
  align-items: flex-start;
  gap: 1rem;
}

.tech-icon {
  display: grid;
  flex-shrink: 0;
  place-items: center;
  width: 2.25rem;
  height: 2.25rem;
  border: 1px solid var(--border);
  border-radius: 0.375rem;
  color: var(--primary);
}

.tech-grid h3 {
  font-size: 1rem;
  font-weight: 700;
}

.tech-grid p {
  margin-top: 0.375rem;
  font-size: 0.875rem;
  color: var(--muted);
  line-height: 1.7;
}

@media (min-width: 640px) {
  .tech-grid {
    grid-template-columns: 1fr 1fr;
  }
}

/* ── timeline ── */

.timeline {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 2.5rem;
  padding-left: 2rem;
  border-left: 1px solid var(--border);
}

.timeline li {
  position: relative;
}

.timeline li::before {
  content: "";
  position: absolute;
  left: -2.35rem;
  top: 0.375rem;
  width: 0.625rem;
  height: 0.625rem;
  border: 2px solid var(--primary);
  border-radius: 50%;
  background: var(--bg);
}

.timeline h3 {
  font-size: 1rem;
  font-weight: 700;
}

.timeline p {
  margin-top: 0.375rem;
  font-size: 0.875rem;
  color: var(--muted);
  line-height: 1.7;
}

/* ── download ── */

.download-inner {
  text-align: center;
}

.qr-row {
  display: flex;
  justify-content: center;
  gap: 2rem;
  margin-top: 2.25rem;
}

.qr-row figure {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
}

.qr-row img {
  width: 108px;
  height: 108px;
  padding: 0.375rem;
  border: 1px solid var(--border);
  border-radius: 0.375rem;
  background: #fff;
}

.qr-row figcaption {
  font-size: 0.75rem;
  color: var(--muted);
}

.qr-note {
  margin-top: 1rem !important;
  font-size: 0.75rem;
  color: var(--muted-soft);
}

/* ── footer ── */

.site-footer {
  border-top: 1px solid var(--border);
  padding: 3.5rem 0 2rem;
}

.footer-grid {
  display: grid;
  gap: 2.5rem;
}

.footer-slogan {
  margin-top: 0.75rem;
  font-size: 0.875rem;
  color: var(--muted);
}

.footer-label {
  display: block;
  margin-bottom: 0.25rem;
  font-size: 0.875rem;
  font-weight: 700;
}

.footer-grid nav,
.footer-grid #contact {
  display: flex;
  flex-direction: column;
  gap: 0.625rem;
  font-size: 0.875rem;
}

.footer-grid nav a,
.footer-grid #contact a {
  color: var(--muted);
  transition: color 0.15s;
}

.footer-grid nav a:hover,
.footer-grid #contact a:hover {
  color: var(--fg);
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-top: 3rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  font-size: 0.75rem;
  color: var(--muted);
}

@media (min-width: 768px) {
  .footer-grid {
    grid-template-columns: 1.5fr 1fr 1fr 1fr;
  }
}