/* landing.css — plus-guide.fun 免费区样式
   设计系统沿用向导本体：底 #f7f8fc / 文字 #272938 / 主色 #6459d9 / 完成态 #287b66 */

:root {
  --bg: #f7f8fc;
  --ink: #272938;
  --ink-soft: #5b5f72;
  --brand: #6459d9;
  --brand-dark: #5145c4;
  --brand-tint: #f0edfc;
  --done: #287b66;
  --warn: #b45309;
  --line: #e3e2ef;
  --card: #ffffff;
}

* { box-sizing: border-box; }

[hidden] { display: none !important; }

html, body {
  margin: 0;
  padding: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: "Segoe UI", "Microsoft YaHei UI", system-ui, -apple-system, sans-serif;
  font-size: 16px;
  line-height: 1.65;
  -webkit-text-size-adjust: 100%;
}

h1, h2, h3 {
  font-family: "Trebuchet MS", "Microsoft YaHei UI", "Segoe UI", sans-serif;
  line-height: 1.3;
  margin: 0;
}

a { color: var(--brand); }

.wrap {
  width: min(920px, 100% - 2.5rem);
  margin: 0 auto;
}

/* ---------------------------------------------------------------- 顶栏 */

.topbar {
  border-bottom: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.82);
  backdrop-filter: blur(8px);
  position: sticky;
  top: 0;
  z-index: 10;
}

.topbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.7rem 0;
}

.brand {
  display: flex;
  align-items: center;
  gap: 0.55rem;
  font-weight: 700;
  font-family: "Trebuchet MS", "Microsoft YaHei UI", sans-serif;
  letter-spacing: 0.01em;
}

.brand-mark {
  width: 30px;
  height: 30px;
  border-radius: 9px;
  background: var(--brand);
  color: #fff;
  display: grid;
  place-items: center;
  font-size: 17px;
  line-height: 1;
}

.topbar-actions { display: flex; align-items: center; gap: 0.5rem; }

/* ---------------------------------------------------------------- 按钮 */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  border: 1px solid transparent;
  border-radius: 10px;
  padding: 0.62rem 1.15rem;
  font-size: 0.95rem;
  font-weight: 600;
  font-family: inherit;
  cursor: pointer;
  text-decoration: none;
  transition: background 0.15s, border-color 0.15s, transform 0.1s;
}

.btn:active { transform: translateY(1px); }

.btn-primary { background: var(--brand); color: #fff; }
.btn-primary:hover { background: var(--brand-dark); }

.btn-ghost {
  background: #fff;
  color: var(--ink);
  border-color: var(--line);
}
.btn-ghost:hover { border-color: var(--brand); color: var(--brand); }

.btn[disabled] { opacity: 0.5; cursor: not-allowed; }

/* ---------------------------------------------------------------- Hero */

.hero { padding: 3.4rem 0 2.2rem; }

.hero-kicker {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  background: var(--brand-tint);
  color: var(--brand-dark);
  border-radius: 999px;
  padding: 0.3rem 0.85rem;
  font-size: 0.83rem;
  font-weight: 600;
  margin-bottom: 1.1rem;
}

.hero h1 {
  font-size: clamp(1.7rem, 4.4vw, 2.5rem);
  letter-spacing: -0.01em;
}

.hero h1 em {
  font-style: normal;
  color: var(--brand);
}

.hero-lead {
  margin: 1rem 0 0;
  font-size: 1.06rem;
  color: var(--ink-soft);
  max-width: 44em;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin-top: 1.7rem;
}

.hero-note {
  margin-top: 0.9rem;
  font-size: 0.86rem;
  color: var(--ink-soft);
}

/* ---------------------------------------------------------------- 数据条 */

.stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 0.9rem;
  margin: 2.4rem 0 0;
}

.stat {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 1rem 1.1rem;
}

.stat-num {
  font-size: 1.5rem;
  font-weight: 700;
  font-family: "Trebuchet MS", "Microsoft YaHei UI", sans-serif;
  color: var(--brand);
}

.stat-label { font-size: 0.86rem; color: var(--ink-soft); }

/* ---------------------------------------------------------------- 区块 */

.section { padding: 2.6rem 0 0; }

.section-title {
  font-size: 1.32rem;
  margin-bottom: 0.4rem;
}

.section-sub {
  color: var(--ink-soft);
  margin: 0 0 1.4rem;
  font-size: 0.96rem;
}

.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1rem;
}

.card {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 1.15rem 1.25rem;
}

.card h3 { font-size: 1.02rem; margin-bottom: 0.35rem; }
.card p { margin: 0; color: var(--ink-soft); font-size: 0.93rem; }

.card-icon {
  width: 34px;
  height: 34px;
  border-radius: 10px;
  background: var(--brand-tint);
  color: var(--brand);
  display: grid;
  place-items: center;
  margin-bottom: 0.7rem;
  font-size: 17px;
}

/* ---------------------------------------------------------------- 目录 */

.phases {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 1rem;
}

.phase {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 1.1rem 1.2rem;
}

.phase-head {
  display: flex;
  align-items: baseline;
  gap: 0.5rem;
  margin-bottom: 0.7rem;
}

.phase-num {
  font-size: 0.76rem;
  font-weight: 700;
  color: var(--brand);
  background: var(--brand-tint);
  border-radius: 6px;
  padding: 0.1rem 0.42rem;
}

.phase-name { font-weight: 700; font-size: 1rem; }

.phase ol {
  margin: 0;
  padding-left: 1.15rem;
  color: var(--ink-soft);
  font-size: 0.92rem;
}

.phase ol li { margin-bottom: 0.22rem; }

.phase ol li strong { color: var(--ink); font-weight: 600; }

/* ---------------------------------------------------------------- 解锁 */

.unlock {
  background: linear-gradient(180deg, #ffffff 0%, #fafaff 100%);
  border: 1px solid var(--line);
  border-radius: 18px;
  padding: 1.9rem;
  margin-top: 2.6rem;
  box-shadow: 0 10px 30px -18px rgba(100, 89, 217, 0.45);
}

.unlock h2 { font-size: 1.28rem; }

.unlock p.unlock-sub {
  color: var(--ink-soft);
  margin: 0.5rem 0 1.3rem;
  font-size: 0.96rem;
}

.key-row {
  display: flex;
  gap: 0.6rem;
  flex-wrap: wrap;
}

.key-input {
  flex: 1 1 260px;
  min-width: 0;
  border: 1px solid var(--line);
  border-radius: 10px;
  padding: 0.68rem 0.85rem;
  font-size: 1rem;
  font-family: ui-monospace, "Cascadia Mono", Consolas, monospace;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  background: #fff;
  color: var(--ink);
}

.key-input:focus {
  outline: none;
  border-color: var(--brand);
  box-shadow: 0 0 0 3px rgba(100, 89, 217, 0.16);
}

.key-input[aria-invalid="true"] { border-color: #dc2626; }

.key-submit { white-space: nowrap; }

.key-hint {
  margin-top: 0.85rem;
  font-size: 0.86rem;
  color: var(--ink-soft);
}

.key-error {
  margin-top: 0.85rem;
  padding: 0.6rem 0.85rem;
  border-radius: 10px;
  background: #fef2f2;
  color: #b91c1c;
  font-size: 0.9rem;
  border: 1px solid #fecaca;
}

.key-ok {
  margin-top: 0.85rem;
  padding: 0.6rem 0.85rem;
  border-radius: 10px;
  background: #ecfdf5;
  color: var(--done);
  font-size: 0.9rem;
  border: 1px solid #a7f3d0;
}

/* ---------------------------------------------------------------- FAQ */

.faq-item {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 0.85rem 1.05rem;
  margin-bottom: 0.6rem;
}

.faq-item summary {
  cursor: pointer;
  font-weight: 600;
  font-size: 0.98rem;
  list-style: none;
}

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

.faq-item summary::before {
  content: "＋";
  color: var(--brand);
  margin-right: 0.5rem;
  font-weight: 700;
}

.faq-item[open] summary::before { content: "－"; }

.faq-item p {
  margin: 0.6rem 0 0.2rem;
  color: var(--ink-soft);
  font-size: 0.92rem;
}

/* ---------------------------------------------------------------- 页脚 */

.footer {
  margin-top: 3rem;
  padding: 1.6rem 0 2.6rem;
  border-top: 1px solid var(--line);
  color: var(--ink-soft);
  font-size: 0.85rem;
}

.footer p { margin: 0.4rem 0; }
.footer-links { display: flex; flex-wrap: wrap; gap: 1rem; margin-top: 0.7rem; }

/* ---------------------------------------------------------------- 窄屏 */

@media (max-width: 640px) {
  .hero { padding: 2.2rem 0 1.6rem; }
  .unlock { padding: 1.3rem; }
  .key-row { flex-direction: column; }
  .key-input, .key-submit { width: 100%; }
  .topbar-actions .btn-ghost { display: none; }
}

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; }
}