:root {
  --bg: #f3ead8;
  --bg-soft: #fbf7ef;
  --panel: rgba(251, 247, 239, 0.9);
  --ink: #1d1a17;
  --ink-soft: #5c544c;
  --wood: #c89e63;
  --wood-deep: #a7753d;
  --line: #2f261c;
  --line-soft: rgba(47, 38, 28, 0.12);
  --black-stone: #161616;
  --white-stone: #f8f5ee;
  --accent: #2f5442;
  --accent-soft: rgba(47, 84, 66, 0.1);
  --danger: #8e3b32;
  --success: #426a46;
  --warning: #7f6031;
  --shadow: 0 24px 60px rgba(58, 38, 12, 0.12);
  --shadow-strong: 0 20px 50px rgba(18, 12, 7, 0.28);
  --radius-xl: 28px;
  --radius-lg: 24px;
  --radius-md: 18px;
  --radius-pill: 999px;
  --transition: 180ms ease;
}

* {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--ink);
  font-family: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  background:
    radial-gradient(circle at top, rgba(255, 255, 255, 0.48), transparent 24%),
    linear-gradient(180deg, rgba(255, 255, 255, 0.5), rgba(255, 255, 255, 0.18)),
    url("./assets/board-wood-texture.png") center top / cover fixed;
}

button,
input,
select {
  font: inherit;
}

button {
  cursor: pointer;
}

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

.app-shell {
  min-height: 100vh;
  backdrop-filter: blur(6px);
}

.topbar {
  position: sticky;
  top: 0;
  z-index: 30;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  padding: 18px clamp(18px, 4vw, 42px);
  background: rgba(251, 247, 239, 0.86);
  border-bottom: 1px solid rgba(47, 38, 28, 0.08);
  backdrop-filter: blur(14px);
}

.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}

.brand-mark {
  width: 52px;
  height: 52px;
  display: grid;
  place-items: center;
  border-radius: 18px;
  background: linear-gradient(160deg, rgba(47, 84, 66, 0.16), rgba(167, 117, 61, 0.22));
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.7);
  font-family: "Noto Serif SC", "Source Han Serif SC", "Songti SC", serif;
  font-size: 26px;
}

.brand-text {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.brand-text strong {
  font-family: "Noto Serif SC", "Source Han Serif SC", "Songti SC", serif;
  font-size: 1.1rem;
}

.brand-text small {
  color: var(--ink-soft);
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 8px;
}

.site-nav a,
.nav-toggle {
  padding: 10px 14px;
  border-radius: 999px;
  transition: background var(--transition), color var(--transition), transform var(--transition);
}

.site-nav a:hover,
.site-nav a.active,
.nav-toggle:hover {
  background: rgba(47, 84, 66, 0.1);
  color: var(--accent);
}

.nav-toggle {
  display: none;
  border: 1px solid rgba(47, 38, 28, 0.12);
  background: rgba(255, 255, 255, 0.6);
}

.main-content {
  padding: 32px clamp(18px, 4vw, 42px) 80px;
}

.page {
  display: none;
  animation: page-in 280ms ease;
}

.page.active {
  display: block;
}

@keyframes page-in {
  from {
    opacity: 0;
    transform: translateY(10px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.panel,
.hero-card,
.feature-card,
.intro-strip {
  border-radius: var(--radius-lg);
  background: var(--panel);
  border: 1px solid rgba(47, 38, 28, 0.08);
  box-shadow: var(--shadow);
}

.hero-card {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 24px;
  padding: clamp(24px, 4vw, 42px);
  overflow: hidden;
}

.hero-copy {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 18px;
}

.hero-copy h1,
.section-heading h2 {
  margin: 0;
  font-family: "Noto Serif SC", "Source Han Serif SC", "Songti SC", serif;
}

.hero-copy h1 {
  font-size: clamp(2.6rem, 6vw, 5rem);
  line-height: 1.08;
}

.hero-summary,
.section-heading p,
.feature-card p,
.intro-strip p,
.empty-box span,
.network-box span,
.login-tip,
.mode-summary,
.field span,
.muted,
.review-meta span,
.profile-login p {
  color: var(--ink-soft);
  line-height: 1.75;
}

.hero-kicker,
.eyebrow {
  margin: 0;
  color: var(--accent);
  font-size: 0.92rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
}

.hero-actions,
.button-grid,
.button-column,
.pill-row,
.choice-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.button {
  min-height: 48px;
  padding: 0 20px;
  border-radius: var(--radius-pill);
  border: 1px solid transparent;
  transition: transform var(--transition), background var(--transition), border-color var(--transition), color var(--transition), box-shadow var(--transition);
}

.button:hover,
.button:focus-visible,
.choice-card:hover,
.pill:hover {
  transform: translateY(-1px);
}

.button:focus-visible,
.choice-card:focus-visible,
.pill:focus-visible,
.go-point:focus-visible,
.nav-toggle:focus-visible,
.site-nav a:focus-visible {
  outline: 3px solid rgba(47, 84, 66, 0.28);
  outline-offset: 2px;
}

.button-primary {
  background: linear-gradient(135deg, var(--ink), #3b2e20);
  color: #fff;
  box-shadow: 0 14px 24px rgba(29, 26, 23, 0.18);
}

.button-primary:hover {
  box-shadow: 0 18px 30px rgba(29, 26, 23, 0.24);
}

.button-secondary {
  background: rgba(255, 255, 255, 0.64);
  border-color: rgba(47, 38, 28, 0.12);
  color: var(--ink);
}

.button-ghost {
  background: rgba(47, 84, 66, 0.08);
  color: var(--accent);
}

.hero-visual img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
  border-radius: var(--radius-xl);
}

.intro-strip {
  margin-top: 24px;
  padding: 22px 24px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.section-heading {
  margin: 40px 0 24px;
}

.feature-grid,
.rules-grid,
.profile-grid {
  display: grid;
  gap: 18px;
}

.feature-grid {
  grid-template-columns: repeat(5, minmax(0, 1fr));
}

.feature-card {
  padding: 24px;
}

.feature-card h3,
.panel h3,
.profile-login h3 {
  margin: 0 0 10px;
  font-family: "Noto Serif SC", "Source Han Serif SC", "Songti SC", serif;
}

.lobby-grid,
.review-layout,
.play-layout {
  display: grid;
  gap: 18px;
}

.lobby-grid {
  grid-template-columns: 1.6fr 0.9fr;
}

.play-layout {
  grid-template-columns: minmax(0, 1.35fr) minmax(320px, 0.75fr);
  align-items: start;
}

.review-layout {
  grid-template-columns: 0.95fr 1.2fr;
}

.stack-gap {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.panel {
  padding: 24px;
}

.choice-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.choice-card,
.pill {
  border: 1px solid rgba(47, 38, 28, 0.12);
  background: rgba(255, 255, 255, 0.56);
  color: var(--ink);
}

.choice-card {
  min-height: 124px;
  padding: 18px;
  text-align: left;
  border-radius: 22px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  transition: transform var(--transition), background var(--transition), border-color var(--transition), box-shadow var(--transition);
}

.choice-card.active,
.pill.active {
  border-color: rgba(47, 84, 66, 0.42);
  background: linear-gradient(135deg, rgba(47, 84, 66, 0.14), rgba(200, 158, 99, 0.18));
  box-shadow: inset 0 0 0 1px rgba(47, 84, 66, 0.1);
}

.choice-card span {
  color: var(--ink-soft);
  line-height: 1.7;
}

.pill {
  min-height: 42px;
  padding: 0 16px;
  border-radius: var(--radius-pill);
}

.form-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.field input,
.field select {
  min-height: 48px;
  padding: 0 14px;
  border-radius: 16px;
  border: 1px solid rgba(47, 38, 28, 0.12);
  background: rgba(255, 255, 255, 0.8);
}

.field-checkbox {
  flex-direction: row;
  align-items: center;
  gap: 10px;
}

.field-checkbox input {
  min-height: auto;
}

.lobby-side {
  justify-content: space-between;
}

.empty-box,
.network-box,
.login-tip,
.board-hint {
  padding: 16px 18px;
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.56);
  border: 1px solid rgba(47, 38, 28, 0.08);
}

.empty-box {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.button-column {
  flex-direction: column;
}

.status-row {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 16px;
}

.status-chip {
  display: inline-flex;
  align-items: center;
  min-height: 38px;
  padding: 0 14px;
  border-radius: var(--radius-pill);
  background: rgba(47, 84, 66, 0.12);
  color: var(--accent);
  font-weight: 700;
}

.board-scroll {
  overflow-x: auto;
  padding-bottom: 4px;
}

.go-board {
  --board-size: min(72vw, 760px);
  position: relative;
  width: var(--board-size);
  aspect-ratio: 1;
  margin: 18px auto 6px;
  border-radius: 28px;
  background:
    linear-gradient(135deg, rgba(255, 255, 255, 0.18), rgba(0, 0, 0, 0.05)),
    url("./assets/board-wood-texture.png") center / cover;
  box-shadow:
    inset 0 2px 0 rgba(255, 255, 255, 0.32),
    inset 0 -10px 16px rgba(117, 74, 28, 0.12),
    0 20px 44px rgba(77, 48, 17, 0.16);
}

.go-board.current-black {
  --preview-fill: rgba(0, 0, 0, 0.18);
  --preview-stroke: rgba(255, 255, 255, 0.08);
}

.go-board.current-white {
  --preview-fill: rgba(255, 255, 255, 0.72);
  --preview-stroke: rgba(29, 26, 23, 0.12);
}

.go-board::before {
  content: "";
  position: absolute;
  inset: 16px;
  border-radius: 24px;
  background-image: var(--board-grid);
  background-size: cover;
  opacity: 0.98;
}

.go-point {
  position: absolute;
  transform: translate(-50%, -50%);
  border: 0;
  border-radius: 50%;
  background: transparent;
  z-index: 2;
}

.go-board.interactive .go-point.empty:hover::before,
.go-point.touch-preview::before {
  content: "";
  position: absolute;
  inset: 18%;
  border-radius: 50%;
  background: var(--preview-fill, rgba(0, 0, 0, 0.18));
  box-shadow: inset 0 0 0 1px var(--preview-stroke, rgba(255, 255, 255, 0.08));
}

.go-point.touch-preview::after {
  content: "确认";
  position: absolute;
  left: 50%;
  top: -26px;
  transform: translateX(-50%);
  min-width: 46px;
  padding: 2px 8px;
  border-radius: 999px;
  background: rgba(29, 26, 23, 0.88);
  color: #fff;
  font-size: 0.7rem;
  letter-spacing: 0.04em;
}

.stone {
  position: absolute;
  inset: 14%;
  border-radius: 50%;
  animation: stone-drop 140ms ease;
}

.stone.black {
  background:
    radial-gradient(circle at 32% 26%, rgba(255, 255, 255, 0.24), transparent 18%),
    radial-gradient(circle at 56% 70%, #232323 0%, #111 60%, #020202 100%);
  box-shadow: 0 7px 18px rgba(0, 0, 0, 0.28);
}

.stone.white {
  background:
    radial-gradient(circle at 28% 24%, rgba(255, 255, 255, 0.96), rgba(255, 255, 255, 0.7) 20%, transparent 28%),
    radial-gradient(circle at 52% 70%, #fff 0%, #f6f1e7 62%, #d8d0c5 100%);
  box-shadow: 0 7px 18px rgba(74, 58, 36, 0.18);
}

.go-point.last-move .last-marker {
  position: absolute;
  inset: 38%;
  border-radius: 50%;
  background: rgba(230, 90, 39, 0.95);
  box-shadow: 0 0 0 3px rgba(255, 241, 224, 0.9);
}

.go-point.last-move .last-marker.on-white {
  background: rgba(45, 37, 29, 0.94);
}

@keyframes stone-drop {
  from {
    opacity: 0.4;
    transform: scale(0.7);
  }

  to {
    opacity: 1;
    transform: scale(1);
  }
}

.info-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.info-item {
  padding: 14px 16px;
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.62);
  border: 1px solid rgba(47, 38, 28, 0.08);
}

.info-item span {
  display: block;
  color: var(--ink-soft);
  font-size: 0.88rem;
  margin-bottom: 4px;
}

.info-item strong {
  font-size: 1.02rem;
}

.mode-summary {
  padding: 16px 18px;
  border-radius: 18px;
  background: rgba(47, 84, 66, 0.08);
  border: 1px solid rgba(47, 84, 66, 0.1);
}

.side-panel {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.button-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.replay-list-panel,
.replay-stage {
  min-height: 100%;
}

.subheading-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 12px;
}

.replay-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.replay-item {
  width: 100%;
  padding: 16px;
  border-radius: 20px;
  border: 1px solid rgba(47, 38, 28, 0.1);
  background: rgba(255, 255, 255, 0.62);
  text-align: left;
  transition: transform var(--transition), border-color var(--transition), box-shadow var(--transition);
}

.replay-item.active,
.replay-item:hover {
  border-color: rgba(47, 84, 66, 0.28);
  box-shadow: 0 14px 28px rgba(47, 84, 66, 0.08);
}

.replay-item strong,
.rule-card h3 {
  display: block;
  margin-bottom: 8px;
}

.replay-item span {
  display: block;
  color: var(--ink-soft);
  line-height: 1.65;
}

.saved-empty {
  color: var(--ink-soft);
  margin-bottom: 10px;
}

.review-stage {
  display: flex;
  flex-direction: column;
  gap: 18px;
}

.review-board-wrap {
  overflow-x: auto;
}

.go-board-review {
  --board-size: min(68vw, 700px);
  margin-top: 0;
}

.review-meta {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  flex-wrap: wrap;
}

#review-slider {
  width: 100%;
}

.rules-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.rule-card {
  padding: 22px;
  border-radius: var(--radius-lg);
  background: var(--panel);
  border: 1px solid rgba(47, 38, 28, 0.08);
  box-shadow: var(--shadow);
}

.rule-card p {
  color: var(--ink-soft);
  line-height: 1.75;
}

.mini-board {
  --mini-size: 160px;
  position: relative;
  width: var(--mini-size);
  aspect-ratio: 1;
  margin-top: 16px;
  border-radius: 18px;
  background:
    linear-gradient(135deg, rgba(255, 255, 255, 0.18), rgba(0, 0, 0, 0.04)),
    url("./assets/board-wood-texture.png") center / cover;
}

.mini-board::before {
  content: "";
  position: absolute;
  inset: 10px;
  border-radius: 14px;
  background-image: var(--mini-grid);
  background-size: cover;
}

.mini-point {
  position: absolute;
  transform: translate(-50%, -50%);
  border-radius: 50%;
  z-index: 2;
}

.mini-point.black {
  background: radial-gradient(circle at 30% 24%, rgba(255, 255, 255, 0.24), transparent 18%), #111;
}

.mini-point.white {
  background: radial-gradient(circle at 26% 22%, rgba(255, 255, 255, 0.98), rgba(255, 255, 255, 0.7) 20%, transparent 28%), #f6f2e9;
  border: 1px solid rgba(29, 26, 23, 0.12);
}

.rules-cta {
  margin-top: 24px;
}

.table-wrap {
  overflow-x: auto;
}

.leaderboard-table {
  width: 100%;
  border-collapse: collapse;
}

.leaderboard-table th,
.leaderboard-table td {
  padding: 14px 12px;
  border-bottom: 1px solid rgba(47, 38, 28, 0.08);
  text-align: left;
}

.profile-grid {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.profile-summary,
.profile-login,
.profile-recent,
.profile-settings {
  min-height: 100%;
}

.summary-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.summary-item {
  padding: 14px 16px;
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.6);
  border: 1px solid rgba(47, 38, 28, 0.08);
}

.settings-list,
.recent-list {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.recent-item {
  padding: 14px 16px;
  border-radius: 18px;
  border: 1px solid rgba(47, 38, 28, 0.08);
  background: rgba(255, 255, 255, 0.6);
}

.site-footer {
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
  justify-content: center;
  padding: 24px;
  color: var(--ink-soft);
  border-top: 1px solid rgba(47, 38, 28, 0.08);
  background: rgba(251, 247, 239, 0.76);
}

.toast-host {
  position: fixed;
  right: 18px;
  bottom: 18px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  z-index: 50;
}

.toast {
  min-width: 240px;
  max-width: 320px;
  padding: 14px 16px;
  border-radius: 18px;
  color: #fff;
  box-shadow: var(--shadow-strong);
  animation: toast-in 180ms ease;
}

.toast.info {
  background: rgba(29, 26, 23, 0.92);
}

.toast.success {
  background: rgba(66, 106, 70, 0.94);
}

.toast.error {
  background: rgba(142, 59, 50, 0.94);
}

@keyframes toast-in {
  from {
    opacity: 0;
    transform: translateY(8px);
  }

  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.modal {
  position: fixed;
  inset: 0;
  z-index: 60;
  display: grid;
  place-items: center;
  padding: 20px;
  background: rgba(22, 18, 12, 0.46);
  backdrop-filter: blur(10px);
}

.modal.hidden {
  display: none;
}

.modal-card {
  position: relative;
  width: min(560px, 100%);
  padding: 28px;
  border-radius: 28px;
  background: rgba(251, 247, 239, 0.96);
  box-shadow: var(--shadow-strong);
}

.modal-close {
  position: absolute;
  top: 16px;
  right: 16px;
  width: 38px;
  height: 38px;
  border: 0;
  border-radius: 50%;
  background: rgba(47, 38, 28, 0.08);
}

.result-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
  margin: 18px 0;
}

.result-stat {
  padding: 14px;
  border-radius: 18px;
  background: rgba(255, 255, 255, 0.72);
  border: 1px solid rgba(47, 38, 28, 0.08);
}

@media (max-width: 1279px) {
  .feature-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .lobby-grid,
  .review-layout,
  .play-layout,
  .profile-grid,
  .rules-grid {
    grid-template-columns: 1fr;
  }

  .go-board,
  .go-board-review {
    --board-size: min(86vw, 720px);
  }
}

@media (max-width: 899px) {
  .hero-card {
    grid-template-columns: 1fr;
  }

  .feature-grid,
  .choice-grid,
  .rules-grid {
    grid-template-columns: 1fr;
  }

  .form-grid,
  .info-list,
  .summary-grid,
  .button-grid {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 767px) {
  .topbar {
    position: static;
    flex-wrap: wrap;
  }

  .nav-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }

  .site-nav {
    display: none;
    width: 100%;
    flex-direction: column;
    align-items: stretch;
    padding-top: 8px;
  }

  .site-nav.open {
    display: flex;
  }

  .site-nav a {
    background: rgba(255, 255, 255, 0.5);
  }

  .intro-strip {
    flex-direction: column;
    align-items: flex-start;
  }

  .hero-actions,
  .pill-row {
    width: 100%;
  }

  .hero-actions .button,
  .pill {
    flex: 1 1 auto;
  }

  .main-content {
    padding-top: 24px;
  }

  .go-board,
  .go-board-review {
    --board-size: min(92vw, 520px);
  }

  .modal-card {
    padding: 22px;
  }
}