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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  color: var(--ink);
  background: var(--bg);
  font-family: var(--sans);
  font-size: 17px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

img {
  max-width: 100%;
}

a {
  color: var(--accent-deep);
  text-decoration-thickness: 1px;
  text-underline-offset: 3px;
}

a:hover {
  color: var(--ink);
}

.wrap {
  width: min(var(--wrap), calc(100% - 40px));
  margin-inline: auto;
}

.kicker {
  margin: 0 0 10px;
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--muted);
  font-family: var(--sans);
}

h1,
h2,
h3,
.serif {
  font-family: var(--serif);
  font-weight: 600;
  letter-spacing: 0.01em;
}

h1 {
  margin: 0;
  line-height: 1.25;
}

h2 {
  margin: 0 0 12px;
  font-size: clamp(28px, 4vw, 40px);
  line-height: 1.3;
}

h3 {
  margin: 0 0 8px;
  font-size: 22px;
}

p {
  margin: 0 0 1em;
}

p:last-child {
  margin-bottom: 0;
}

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

.scheme-note {
  margin: 0;
  padding: 8px 16px;
  text-align: center;
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--paper);
  background: var(--ink);
}

.scheme-note a {
  color: #f3d7a0;
}

/* —— Nav —— */
.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  padding: 22px 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  color: inherit;
  text-decoration: none;
}

.brand:hover {
  color: inherit;
}

.brand-mark {
  display: block;
  width: 32px;
  height: 32px;
  border-radius: 7px;
  flex-shrink: 0;
}

.brand-name {
  font-family: var(--serif);
  font-size: 22px;
  font-weight: 700;
}

.brand-tag {
  font-size: 13px;
  color: var(--muted);
}

.nav-links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 22px;
  font-size: 14px;
}

.nav-links a {
  color: var(--ink);
  text-decoration: none;
}

.nav-links a:hover {
  color: var(--accent-deep);
}

.nav-links a.nav-download {
  color: var(--accent-deep);
  font-weight: 600;
}

.nav-links a.nav-research {
  color: var(--accent-deep);
  font-weight: 700;
  text-decoration: none;
  padding: 3px 10px;
  border-radius: 999px;
  background: #e8f8ef;
}

.nav-auth {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
  font-size: 14px;
}

.nav-auth-login,
.nav-auth-report {
  color: var(--accent-deep);
  font-weight: 600;
  text-decoration: none;
}

.nav-auth-login:hover,
.nav-auth-report:hover {
  color: var(--ink);
}

.nav-auth-user {
  display: flex;
  align-items: center;
  gap: 10px;
}

.nav-auth-name {
  color: var(--muted);
  max-width: 11em;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}

/* —— Buttons —— */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 22px;
  border-radius: var(--radius-btn);
  border: 1px solid transparent;
  font-family: inherit;
  font-size: 15px;
  text-decoration: none;
  cursor: pointer;
}

.btn-primary {
  color: var(--paper);
  background: var(--accent-deep);
}

.btn-primary:hover {
  color: var(--paper);
  filter: brightness(1.08);
}

.btn-ghost {
  color: var(--ink);
  background: transparent;
  border-color: var(--line);
}

.btn-ghost:hover {
  color: var(--ink);
  background: var(--paper);
}

.btn-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.download-row {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
  margin: 0 0 22px;
}

.download-meta {
  font-size: 13px;
  color: var(--muted);
  line-height: 1.5;
}

.req-banner {
  margin: 20px auto 0;
  max-width: 38em;
  padding: 14px 18px;
  font-size: 16px;
  line-height: 1.65;
  color: var(--ink);
  background: rgba(110, 42, 42, 0.06);
  border: 1px solid rgba(110, 42, 42, 0.22);
  border-radius: 8px;
}

.req-banner a {
  font-weight: 600;
}

.chrome-dl {
  display: block;
  margin-top: 8px;
}

.chrome-dl a {
  margin-right: 14px;
}

.chrome-dl a:last-child {
  margin-right: 0;
}

.guide {
  list-style: none;
  margin: 8px 0 8px;
  padding: 0;
  counter-reset: guide;
}

.guide > li {
  counter-increment: guide;
  padding: 28px 0 32px;
  border-bottom: 1px solid var(--line);
}

.guide > li:last-child {
  border-bottom: 0;
  padding-bottom: 12px;
}

.guide h3 {
  margin: 0 0 8px;
  font-family: var(--serif);
  font-size: 22px;
  font-weight: 600;
}

.guide h3::before {
  content: counter(guide, decimal-leading-zero) "　";
  font-size: 13px;
  letter-spacing: 0.16em;
  color: var(--accent);
  font-weight: 500;
}

.guide p {
  margin: 0 0 16px;
  max-width: 40em;
  color: var(--muted);
  font-size: 16px;
  line-height: 1.65;
}

.guide figure {
  margin: 0;
}

.guide img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--paper);
}

/* —— Video placeholder —— */
.video-block {
  margin: 0;
}

.video-stage {
  position: relative;
  display: grid;
  place-items: center;
  min-height: 280px;
  aspect-ratio: 16 / 10;
  overflow: hidden;
  color: var(--paper);
  background:
    radial-gradient(ellipse at 30% 20%, rgba(255, 220, 160, 0.22), transparent 50%),
    linear-gradient(160deg, #4a3b2c, #2a221b 55%, #1c1713);
}

.video-stage::after {
  content: "";
  position: absolute;
  inset: 0;
  background:
    repeating-linear-gradient(
      -18deg,
      transparent,
      transparent 18px,
      rgba(255, 255, 255, 0.03) 18px,
      rgba(255, 255, 255, 0.03) 19px
    );
  pointer-events: none;
}

.play {
  position: relative;
  z-index: 1;
  width: 72px;
  height: 72px;
  border: 0;
  border-radius: 50%;
  background: rgba(255, 248, 238, 0.94);
  color: var(--ink);
  cursor: default;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.28);
}

.play::before {
  content: "";
  display: block;
  margin-left: 6px;
  border-style: solid;
  border-width: 12px 0 12px 20px;
  border-color: transparent transparent transparent currentColor;
}

.howto-video {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: contain;
  background: #1c1713;
  border: 0;
}

.video-caption {
  margin: 12px 4px 0;
  font-size: 13px;
  color: var(--muted);
}

/* —— Sections —— */
.section {
  padding: 84px 0;
}

.section-head {
  max-width: 640px;
  margin-bottom: 36px;
}

.lead {
  font-size: 18px;
  color: var(--muted);
}

hr.rule {
  border: 0;
  height: 1px;
  margin: 0;
  background: var(--line);
}

/* —— Not-this —— */
.not-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.not-card {
  padding: 24px 22px 28px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
}

.not-card strong {
  display: block;
  margin-bottom: 8px;
  font-family: var(--serif);
  font-size: 20px;
}

/* —— Steps —— */
.steps {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 28px;
  counter-reset: step;
}

.step {
  position: relative;
  padding-top: 8px;
}

.step::before {
  counter-increment: step;
  content: counter(step, decimal-leading-zero);
  display: block;
  margin-bottom: 14px;
  font-family: var(--serif);
  font-size: 13px;
  letter-spacing: 0.16em;
  color: var(--accent);
}

/* —— Quotes / report preview —— */
.quotes {
  display: grid;
  gap: 20px;
}

.quote {
  padding: 28px 32px;
  background: var(--paper);
  border-radius: var(--radius-card);
  border: 1px solid var(--line);
}

.quote p {
  font-family: var(--serif);
  font-size: clamp(22px, 2.4vw, 28px);
  line-height: 1.45;
  margin: 0 0 12px;
}

.quote span {
  font-size: 13px;
  color: var(--muted);
}

/* —— Research —— */
.research-list {
  display: grid;
  gap: 16px;
  padding: 0;
  margin: 0;
  list-style: none;
}

.research-list li {
  padding: 18px 0;
  border-top: 1px solid var(--line);
}

.research-list li:last-child {
  border-bottom: 1px solid var(--line);
}

.research-list b {
  font-family: var(--serif);
  font-weight: 600;
}

.disclaimer {
  margin-top: 24px;
  padding: 16px 18px;
  font-size: 14px;
  color: var(--muted);
  background: color-mix(in srgb, var(--paper) 70%, transparent);
  border-left: 3px solid var(--accent);
}

/* —— FAQ —— */
.faq details {
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
}

.faq details:first-child {
  border-top: 1px solid var(--line);
}

.faq summary {
  cursor: pointer;
  font-weight: 600;
  list-style: none;
}

.faq summary::-webkit-details-marker {
  display: none;
}

.faq summary::after {
  content: "+";
  float: right;
  font-weight: 400;
  color: var(--muted);
}

.faq details[open] summary::after {
  content: "–";
}

.faq details p {
  margin: 10px 0 4px;
  color: var(--muted);
  font-size: 16px;
}

/* —— Invite —— */
.invite-box {
  padding: 36px 40px;
  background: var(--paper);
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
}

.invite-form {
  display: grid;
  gap: 12px;
  margin-top: 20px;
  max-width: 420px;
}

.invite-form input,
.invite-form textarea {
  width: 100%;
  padding: 12px 14px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: var(--bg);
  color: var(--ink);
  font: inherit;
}

.invite-form textarea {
  min-height: 88px;
  resize: vertical;
}

.invite-form button {
  justify-self: start;
}

.form-note {
  margin-top: 8px;
  font-size: 13px;
  color: var(--muted);
}

.form-status {
  margin: 12px 0 0;
  font-size: 15px;
  line-height: 1.55;
}

.form-status.ok {
  color: var(--accent-deep);
}

.form-status.err {
  color: #9c3d3d;
}

/* —— Footer —— */
.foot {
  padding: 36px 0 48px;
  font-size: 13px;
  color: var(--muted);
}

.foot-row {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 12px 24px;
}

.foot-brand {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.foot-brand img {
  width: 20px;
  height: 20px;
  border-radius: 5px;
}

.scheme-switch a {
  margin-right: 14px;
  text-decoration: none;
}

/* —— Scheme A: 手账灯 —— */
.scheme-a {
  --wrap: 920px;
  --bg: #f3e8d6;
  --paper: #fff8ee;
  --ink: #3d3428;
  --muted: #7a6e5c;
  --accent: #c48a3a;
  --accent-deep: #8b5a2b;
  --line: #e6d5b8;
  --radius-card: 18px;
  --radius-btn: 999px;
  --serif: "Noto Serif SC", "Songti SC", "STSong", serif;
  --sans: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", sans-serif;
  background-image:
    radial-gradient(ellipse 80% 50% at 10% -10%, rgba(255, 210, 120, 0.35), transparent 50%),
    radial-gradient(ellipse 60% 40% at 100% 0%, rgba(180, 120, 60, 0.12), transparent 45%);
}

.scheme-a .hero {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 48px;
  align-items: center;
  padding: 28px 0 72px;
}

.scheme-a h1 {
  font-size: clamp(36px, 5vw, 52px);
}

.scheme-a .polaroid {
  padding: 14px 14px 48px;
  background: var(--paper);
  border-radius: 4px;
  box-shadow:
    0 1px 0 rgba(255, 255, 255, 0.8) inset,
    0 18px 40px rgba(80, 50, 20, 0.16);
  transform: rotate(1.4deg);
}

.scheme-a .polaroid .video-stage {
  border-radius: 2px;
  min-height: 240px;
}

.scheme-a .tape {
  position: absolute;
  top: -12px;
  left: 28%;
  width: 86px;
  height: 22px;
  background: rgba(232, 196, 120, 0.45);
  transform: rotate(-8deg);
}

.scheme-a .polaroid-wrap {
  position: relative;
}

.scheme-a .not-card,
.scheme-a .quote,
.scheme-a .invite-box {
  box-shadow: 0 10px 28px rgba(90, 60, 20, 0.06);
}

.scheme-a .quote {
  border-left: 4px solid var(--accent);
}

/* —— Scheme B: 午后报告 —— */
.scheme-b {
  --wrap: 980px;
  --bg: #efe0cc;
  --paper: #fbf3e8;
  --ink: #2c2118;
  --muted: #6f5b4a;
  --accent: #c24e2d;
  --accent-deep: #8e351c;
  --line: #e2cdb5;
  --radius-card: 2px;
  --radius-btn: 2px;
  --serif: "Noto Serif SC", "Songti SC", "STSong", serif;
  --sans: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", sans-serif;
}

.scheme-b .nav {
  border-bottom: 1px solid var(--ink);
  padding: 16px 0 12px;
}

.scheme-b .hero {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: 48px;
  padding: 28px 0 24px;
  align-items: end;
}

.scheme-b h1 {
  font-size: clamp(36px, 5.2vw, 54px);
  font-weight: 700;
  line-height: 1.18;
  max-width: 12em;
}

.scheme-b .hero-kicker {
  margin-bottom: 18px;
  font-size: 13px;
  letter-spacing: 0.22em;
  color: var(--accent);
}

.scheme-b .hero-lead {
  max-width: 34em;
  font-size: 17px;
}

.scheme-b .masthead {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding: 10px 0;
  border-top: 2px solid var(--ink);
  border-bottom: 1px solid var(--ink);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--muted);
}

.scheme-b .video-stage {
  min-height: 320px;
}

.scheme-b .quotes {
  grid-template-columns: 1fr 1fr;
}

.scheme-b .quote {
  background: transparent;
  border: 0;
  border-top: 3px solid var(--accent);
  border-radius: 0;
  padding: 22px 8px 8px;
}

.scheme-b .quote p::before {
  content: "「";
  color: var(--accent);
}

.scheme-b .quote p::after {
  content: "」";
  color: var(--accent);
}

.scheme-b .not-grid {
  gap: 0;
}

.scheme-b .not-card {
  border-radius: 0;
  background: transparent;
  border: 0;
  border-right: 1px solid var(--line);
  padding: 8px 28px 8px 0;
}

.scheme-b .not-card:last-child {
  border-right: 0;
  padding-right: 0;
}

.scheme-b .invite-box {
  border-radius: 0;
  border: 1px solid var(--ink);
}

/* —— Scheme C: 一封来信（选定精修） —— */
.scheme-c {
  --wrap: 740px;
  --bg: #c4ae8c;
  --paper: #fbf6ea;
  --ink: #3a2f24;
  --muted: #7d6b56;
  --accent: #9c3d3d;
  --accent-deep: #6e2a2a;
  --line: #e4d4bc;
  --radius-card: 0;
  --radius-btn: 0;
  --serif: "ZCOOL XiaoWei", "Noto Serif SC", "Songti SC", serif;
  --sans: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", sans-serif;
  --script: "Ma Shan Zheng", "ZCOOL XiaoWei", cursive;
  background-color: #c4ae8c;
  background-image:
    radial-gradient(ellipse at 50% -8%, rgba(255, 248, 230, 0.4), transparent 46%),
    repeating-linear-gradient(
      90deg,
      rgba(90, 60, 30, 0.035) 0 1px,
      transparent 1px 7px
    ),
    linear-gradient(180deg, #d7c19d, #c4ae8c 38%, #b79d78);
}

.scheme-c .scheme-note {
  background: transparent;
  color: #6a5438;
  letter-spacing: 0.16em;
  padding: 10px 16px 0;
}

.scheme-c .scheme-note a {
  color: #6e2a2a;
}

.scheme-c .letter {
  position: relative;
  margin: 28px auto 72px;
  padding: 44px 56px 60px;
  background:
    linear-gradient(180deg, rgba(255, 252, 245, 0.55), transparent 28%),
    var(--paper);
  box-shadow:
    0 1px 0 #fffdf6 inset,
    0 0 0 1px rgba(90, 60, 30, 0.08),
    0 28px 60px rgba(60, 40, 20, 0.22);
}

.scheme-c .letter::before {
  content: "";
  position: absolute;
  inset: 14px;
  border: 1px solid rgba(156, 61, 61, 0.18);
  pointer-events: none;
}

.scheme-c .nav {
  position: relative;
  z-index: 1;
  padding-top: 4px;
  margin-bottom: 8px;
  border-bottom: 1px solid var(--line);
}

.scheme-c .letter-meta {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  margin: 18px 0 6px;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--muted);
}

.scheme-c .wax {
  position: relative;
  width: 76px;
  height: 76px;
  margin: 10px auto 8px;
  display: grid;
  place-items: center;
  border-radius: 46% 54% 48% 52%;
  color: #f7e6c8;
  background:
    radial-gradient(circle at 32% 28%, #d46a6a, #8a2e2e 58%, #541818);
  font-family: var(--serif);
  font-size: 30px;
  box-shadow:
    0 1px 0 rgba(255, 200, 180, 0.35) inset,
    0 10px 18px rgba(80, 20, 20, 0.28);
}

.scheme-c .wax::after {
  content: "";
  position: absolute;
  inset: 7px;
  border-radius: inherit;
  border: 1px solid rgba(247, 230, 200, 0.28);
  pointer-events: none;
}

.scheme-c .hero {
  text-align: center;
  padding: 8px 0 28px;
}

.scheme-c h1 {
  font-size: clamp(30px, 4.6vw, 42px);
  line-height: 1.28;
}

.scheme-c .greeting {
  font-family: var(--script);
  font-size: 32px;
  margin-bottom: 12px;
  color: var(--accent-deep);
}

.scheme-c .hero .lead {
  margin: 16px auto 0;
  max-width: 34em;
  font-size: 17px;
}

.scheme-c .hero-cta {
  margin: 20px 0 0;
}

.scheme-c .req-banner {
  text-align: left;
}

.scheme-c .btn-row {
  justify-content: center;
}

.hero-sub {
  margin: 14px 0 0;
  font-size: 14px;
}

.scheme-c .hero-sub {
  text-align: center;
}

.hero-sub a {
  color: var(--accent-deep);
  text-decoration: none;
}

.hero-sub a:hover {
  text-decoration: underline;
}

.scheme-c .envelope {
  position: relative;
  margin: 36px auto 0;
  max-width: 540px;
  padding: 18px 14px 12px;
  background: #f3e6d0;
  border: 1px solid rgba(110, 42, 42, 0.18);
  box-shadow: 0 10px 24px rgba(60, 40, 20, 0.08);
}

.scheme-c .envelope::before {
  content: "";
  position: absolute;
  top: -18px;
  left: 50%;
  width: 72%;
  height: 28px;
  transform: translateX(-50%);
  background: linear-gradient(180deg, #e8d4b6, #f3e6d0);
  clip-path: polygon(0 100%, 50% 0, 100% 100%);
  border-bottom: 0;
}

.scheme-c .video-stage {
  min-height: 250px;
}

.scheme-c .video-block.envelope {
  max-width: 720px;
}

.scheme-c .hero .video-block.envelope {
  margin-top: 28px;
  margin-bottom: 4px;
  max-width: min(100%, 760px);
}

.scheme-c .hero .video-caption {
  text-align: center;
}

.scheme-c .howto-video {
  min-height: 250px;
}

.scheme-c .section {
  padding: 36px 0 8px;
}

.scheme-c .section-head {
  margin-bottom: 20px;
  text-align: center;
  max-width: none;
}

.scheme-c .section-head .lead {
  margin-inline: auto;
  max-width: 36em;
}

.scheme-c .section-head h2 {
  font-size: clamp(24px, 3.4vw, 32px);
}

.scheme-c .trouble-list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.scheme-c .trouble-list li {
  padding: 18px 8px;
  border-bottom: 1px solid var(--line);
  text-align: center;
}

.scheme-c .trouble-list li:first-child {
  border-top: 1px solid var(--line);
}

.scheme-c .trouble-list strong {
  display: block;
  margin-bottom: 6px;
  font-family: var(--serif);
  font-size: 20px;
}

.scheme-c .ai-rounds {
  display: grid;
  gap: 0;
}

.scheme-c .ai-rounds article {
  padding: 18px 4px 18px 0;
  border-bottom: 1px solid var(--line);
}

.scheme-c .ai-rounds article:first-child {
  border-top: 1px solid var(--line);
}

.scheme-c .ai-rounds .n {
  display: block;
  margin-bottom: 6px;
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--accent);
}

.scheme-c .org-row {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 12px;
  margin: 8px 0 20px;
  text-align: center;
}

.scheme-c .org-row span {
  padding: 14px 8px;
  border: 1px solid var(--line);
  font-family: var(--serif);
  font-size: 15px;
  line-height: 1.35;
}

.path-grid {
  display: grid;
  gap: 16px;
  margin-top: 8px;
}

@media (min-width: 720px) {
  .path-grid {
    grid-template-columns: 1.15fr 0.85fr;
    align-items: stretch;
  }
}

.path-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 16px 18px 16px;
  text-align: left;
  border: 1px solid var(--line);
  background: var(--paper);
}

.path-card h3 {
  margin: 0;
  font-size: 19px;
}

.path-card p:last-of-type {
  flex: 1;
  margin-bottom: 8px;
}

.path-tag {
  margin: 0;
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
}

.path-card-primary {
  display: grid;
  grid-template-columns: 1fr auto;
  grid-template-areas:
    "tag btn"
    "title btn"
    "desc btn";
  align-items: center;
  column-gap: 16px;
  border-color: rgba(110, 42, 42, 0.28);
  box-shadow: 0 10px 24px rgba(60, 40, 20, 0.06);
}

.path-card-primary .path-tag {
  grid-area: tag;
  color: var(--accent-deep);
}

.path-card-primary h3 { grid-area: title; }

.path-card-primary p:last-of-type {
  grid-area: desc;
  flex: none;
  margin-bottom: 0;
}

.path-card .btn {
  align-self: flex-start;
}

.path-card-primary .btn {
  grid-area: btn;
  align-self: center;
}

.scheme-c #advanced .req-banner,
.scheme-c #advanced .envelope {
  margin-top: 20px;
}

.scheme-c .quote {
  background: transparent;
  border: 0;
  text-align: center;
  padding: 8px 12px 22px;
}

.scheme-c .quote p {
  font-size: clamp(20px, 2.6vw, 26px);
}

.scheme-c .invite-box {
  background: rgba(255, 248, 238, 0.6);
  border: 1px solid var(--accent);
  text-align: center;
  padding: 32px 28px 28px;
}

.scheme-c .invite-form {
  margin-inline: auto;
  text-align: left;
}

.scheme-c .signoff {
  margin-top: 36px;
  text-align: right;
  font-family: var(--script);
  font-size: 26px;
  color: var(--accent-deep);
}

/* —— Responsive —— */
@media (max-width: 860px) {
  .scheme-a .hero,
  .scheme-b .hero,
  .scheme-b .quotes,
  .not-grid,
  .steps {
    grid-template-columns: 1fr;
  }

  .scheme-a .polaroid {
    transform: none;
    max-width: 420px;
  }

  .scheme-b .not-card {
    border-right: 0;
    border-bottom: 1px solid var(--line);
    padding: 20px 0;
  }

  .scheme-c .letter {
    padding: 28px 22px 40px;
    margin-inline: 12px;
  }

  .scheme-c .letter::before {
    inset: 10px;
  }

  .scheme-c .org-row {
    grid-template-columns: 1fr;
  }

  .nav-links {
    display: flex;
    gap: 12px;
  }

  .nav-links a:not(.nav-research):not(.nav-download) {
    display: none;
  }

  .nav-auth-name {
    max-width: 7em;
  }
}

/* —— 隐私 / 支持 / 研究页 —— */
.legal {
  max-width: 38em;
}

.legal h1 {
  font-size: clamp(28px, 4vw, 36px);
  margin: 8px 0 8px;
}

.legal .updated {
  margin: 0 0 28px;
  font-size: 13px;
  color: var(--muted);
}

.legal h2 {
  font-size: 22px;
  margin: 32px 0 10px;
}

.legal ul {
  margin: 0 0 1em;
  padding-left: 1.2em;
}

.legal li {
  margin: 0 0 0.4em;
}

.foot-links {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
}

.foot-links a {
  color: var(--muted);
  text-decoration: none;
}

.foot-links a:hover {
  color: var(--ink);
}

.research-page {
  max-width: none;
}

.research-page h1 {
  font-size: clamp(28px, 4vw, 40px);
  margin: 8px 0 12px;
}

.research-intro {
  max-width: 36em;
}

.research-page .updated {
  margin: 0 0 28px;
  font-size: 13px;
  color: var(--muted);
}

.research-page h2 {
  font-size: 22px;
  margin: 36px 0 14px;
}

.structure-grid {
  display: grid;
  gap: 12px;
}

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

.structure-card,
.study-card {
  padding: 18px 18px 16px;
  border: 1px solid var(--line);
  background: var(--paper);
}

.structure-card h3,
.study-card h3 {
  margin: 0 0 8px;
  font-size: 18px;
  line-height: 1.4;
}

.study-card h3 {
  margin-bottom: 4px;
}

.study-title-zh {
  margin: 0 0 10px;
  font-size: 15px;
  font-weight: 400;
  color: var(--muted);
  line-height: 1.5;
}

.structure-card p:last-child {
  margin: 0;
  font-size: 14px;
  color: var(--muted);
}

.study-list {
  display: grid;
  gap: 12px;
}

.study-venue {
  margin: 0 0 8px;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
}

.study-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin: 0 0 10px;
}

.study-badges span {
  display: inline-block;
  padding: 2px 8px;
  border-radius: 999px;
  background: #e8f8ef;
  color: var(--accent-deep);
  font-size: 12px;
}

.study-meta {
  margin: 0 0 4px;
  font-size: 14px;
  color: var(--muted);
}

.study-link {
  display: inline-block;
  margin-top: 8px;
  font-size: 14px;
  font-weight: 600;
  color: var(--accent-deep);
  text-decoration: none;
}

.study-link:hover {
  text-decoration: underline;
}

.section#research .lead a,
.research-cta a {
  font-weight: 700;
}

.research-cta {
  margin: 16px 0 0;
}