@import url("Color.css");
@import url("General.css");
@import url("Font.css");

:root {
  --sidebar-width: 220px;
}

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

html,
body {
  margin: 0;
  min-height: 100%;
  background: var(--color-bg-page);
  color: var(--color-text-primary);
}

.container {
  display: flex;
  min-height: 100vh;
}

.lesson-main {
  margin-left: var(--sidebar-width);
  width: calc(100% - var(--sidebar-width));
  min-width: 0;
  padding: clamp(20px, 2.2vw, 32px);
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.lesson-section {
  width: min(100%, 980px);
  margin: 0 auto;
  background: var(--color-bg-panel);
  border: 1px solid var(--color-border-soft);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-card);
  padding: clamp(18px, 1.7vw, 26px);
}

.section-tag {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-accent);
  border: 1px solid var(--color-accent);
  background: rgba(0, 174, 239, 0.1);
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  margin-bottom: 12px;
}

.lesson-section h2 {
  margin: 0 0 16px;
  padding-left: 10px;
  border-left: 4px solid var(--color-accent);
}

.lesson-section h2 + p,
.pieces-intro {
  margin-top: 0;
}

.lesson-section p {
  margin-bottom: 12px;
  color: var(--color-text-muted);
  overflow-wrap: anywhere;
}

.lesson-section strong {
  color: var(--color-text-primary);
}

.lesson-divider {
  width: min(100%, 980px);
  margin: 0 auto;
  border: 0;
  border-top: 1px solid var(--color-border-soft);
  opacity: 0.7;
}

.intro-facts {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(170px, 1fr));
  gap: 12px;
  margin-top: 16px;
}

.fact-card {
  background: var(--color-bg-surface);
  border: 1px solid var(--color-border-default);
  border-radius: var(--radius-sm);
  padding: 12px 14px;
}

.fact-card .fact-num {
  display: block;
  margin-bottom: 4px;
  font-size: 1.45rem;
  font-weight: 700;
  color: var(--color-accent);
}

.fact-card p {
  margin: 0;
  font-size: 0.92rem;
  color: var(--color-text-primary);
}

.rules-list {
  list-style: none;
  margin: 14px 0 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.rules-list li {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  background: var(--color-bg-surface);
  border: 1px solid var(--color-border-default);
  border-left: 4px solid var(--color-accent);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  padding: 10px 12px;
  color: var(--color-text-primary);
}

.rules-list li .rule-n {
  min-width: 24px;
  color: var(--color-accent);
  font-weight: 700;
}

.piece-entry {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(260px, 320px);
  gap: 20px;
  align-items: center;
  margin-bottom: 22px;
  padding-bottom: 22px;
  border-bottom: 1px solid var(--color-border-soft);
}

.piece-entry:last-child {
  margin-bottom: 0;
  padding-bottom: 0;
  border-bottom: none;
}

.piece-entry.reverse {
  direction: rtl;
}

.piece-entry.reverse > * {
  direction: ltr;
}

.piece-info h3 {
  margin: 0 0 8px;
}

.piece-info h3 span {
  color: var(--color-text-muted);
}

.piece-info .piece-kanji {
  display: inline-block;
  margin-bottom: 6px;
  font-size: 1.5rem;
  color: var(--color-accent);
  font-weight: 700;
}

.piece-info p {
  margin-bottom: 0;
}

.promoted-badge {
  display: inline-block;
  margin-top: 10px;
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  border: 1px solid rgba(0, 174, 239, 0.35);
  background: rgba(0, 174, 239, 0.1);
  color: var(--color-text-primary);
  font-size: 0.82rem;
}

.mini-board-wrap {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  background: var(--color-bg-panel-alt);
  border: 1px solid var(--color-border-default);
  border-radius: var(--radius-sm);
  padding: 12px;
}

.mini-board-label {
  color: var(--color-text-muted);
  font-size: 0.78rem;
  text-align: center;
}

.mini-board {
  display: grid;
  background: var(--color-board-bg);
  border: 2px solid var(--color-board-border);
  border-radius: 4px;
  overflow: hidden;
}

.mini-board.b3 {
  grid-template-columns: repeat(3, 56px);
  grid-template-rows: repeat(3, 56px);
}

.mini-board.b5 {
  grid-template-columns: repeat(5, 42px);
  grid-template-rows: repeat(5, 42px);
}

.mc {
  border: 1px solid rgba(0, 0, 0, 0.28);
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
}

.mc.center {
  background: rgba(255, 255, 255, 0.2);
}

.mc.reachable {
  background: var(--color-highlight-legal);
}

.mc.reachable::after {
  content: "";
  position: absolute;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  border: 1.5px solid rgba(0, 0, 0, 0.4);
  background: rgba(255, 255, 255, 0.55);
}

.mc img {
  width: 40px;
  height: 40px;
  object-fit: contain;
  position: relative;
  z-index: 1;
}

.mini-board.b3 .mc img {
  width: 46px;
  height: 46px;
}

.board-toggle {
  display: flex;
  gap: 8px;
}

.board-toggle button {
  border: 1px solid var(--color-border-strong);
  background: var(--color-bg-darkest);
  color: var(--color-text-primary);
  border-radius: var(--radius-sm);
  padding: 6px 12px;
  cursor: pointer;
  min-height: 36px;
  font-size: 0.84rem;
}

.board-toggle button.active,
.board-toggle button:hover {
  background: var(--color-accent);
  border-color: var(--color-accent);
  color: var(--color-white);
}

.win-scenario {
  display: flex;
  gap: 14px;
  align-items: flex-start;
  margin-bottom: 14px;
  padding: 12px;
  background: var(--color-bg-surface);
  border: 1px solid var(--color-border-default);
  border-radius: var(--radius-sm);
}

.win-scenario:last-child {
  margin-bottom: 0;
}

.win-icon {
  min-width: 44px;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  display: grid;
  place-items: center;
  background: var(--color-bg-darkest);
  border: 1px solid var(--color-border-strong);
  font-size: 1.4rem;
}

.win-scenario h3 {
  margin: 2px 0 6px;
}

.win-scenario p {
  margin: 0;
}

.cta-wrap {
  text-align: center;
  padding: 4px 0;
}

.cta-wrap p {
  margin: 0 0 14px;
  color: var(--color-text-muted);
}

.btn-play {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding: 10px 24px;
  border: 1px solid var(--color-accent);
  border-radius: var(--radius-sm);
  text-decoration: none;
  background: var(--color-accent);
  color: var(--color-white);
  font-weight: 700;
  letter-spacing: 0.03em;
  box-shadow: var(--shadow-pop);
}

.btn-play:hover {
  background: var(--color-accent-hover);
  border-color: var(--color-accent-hover);
  transform: translateY(-1px);
}

@media (max-width: 1024px) and (min-width: 901px) {
  .lesson-main {
    padding: 20px;
  }
}

@media (max-width: 900px) {
  .container {
    flex-direction: column;
  }

  .lesson-main {
    margin-left: 0;
    width: min(100%, 980px);
    margin-right: auto;
    margin-bottom: 70px;
    padding: 20px 16px;
  }
}

@media (max-width: 768px) {
  .piece-entry {
    grid-template-columns: 1fr;
    gap: 14px;
  }

  .piece-entry.reverse {
    direction: ltr;
  }
}

@media (max-width: 640px) {
  .lesson-main {
    padding: 16px 12px;
  }

  .lesson-section {
    padding: 14px;
  }

  .mini-board.b3 {
    grid-template-columns: repeat(3, 50px);
    grid-template-rows: repeat(3, 50px);
  }

  .mini-board.b3 .mc img {
    width: 42px;
    height: 42px;
  }
}