:root {
  --ink: #192238;
  --mint: #00cf98;
  --mint-light: #00edb4;
  --cyan: #00c6d9;
  --cyan-light: #22e3f0;
  --x: #f2355b;
  --x-dark: #c7203f;
  --o: #3ea8d8;
  --o-dark: #2a87b6;
  --font: "Open Sans", Arial, sans-serif;
}
* {
  box-sizing: border-box;
}
body {
  margin: 0;
  background: radial-gradient(circle at top, #d7f0ee, #fff7e8 60%);
  font-family: var(--font);
  color: var(--ink);
}
.page {
  min-height: 100vh;
  display: grid;
  place-items: center;
  padding: 20px 12px;
}
.back {
  position: fixed;
  top: 22px;
  left: 24px;
  color: var(--ink);
  font-weight: 700;
  text-decoration: none;
  font-family: Arial, sans-serif;
}

/* Khung game giữ tỉ lệ 760×900; mọi kích thước tính theo cqw */
.stage {
  container-type: inline-size;
  position: relative;
  width: min(100%, 460px, calc((100vh - 40px) * 0.8444));
  width: min(100%, 460px, calc((100dvh - 40px) * 0.8444));
  aspect-ratio: 760 / 900;
  overflow: hidden;
  border-radius: 14px;
  background: #fafafa;
  box-shadow: 0 18px 50px #19223830;
  user-select: none;
  -webkit-user-select: none;
  -webkit-tap-highlight-color: transparent;
}
.scr {
  position: absolute;
  inset: 0;
}
.scr[hidden] {
  display: none;
}
.scr.light {
  background: #fafafa;
}
.scene,
.board {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  display: block;
}

/* Nút viên thuốc xanh bạc hà */
.pill {
  position: absolute;
  left: 25.3%;
  width: 49.4%;
  height: 8.6%;
  border: 0.85cqw solid var(--mint-light);
  border-radius: 999px;
  background: var(--mint);
  color: #fff;
  font: 700 4.7cqw var(--font);
  box-shadow: 0 1.05cqw 0 #b4b4b4;
  cursor: pointer;
  transition: transform 0.08s;
}
.pill:hover {
  filter: brightness(1.04);
}
.pill:active {
  transform: translateY(0.7cqw);
  box-shadow: 0 0.35cqw 0 #b4b4b4;
}

/* Nút tròn xanh ngọc ở góc */
.round {
  position: absolute;
  top: 1.9%;
  width: 10cqw;
  height: 10cqw;
  border: 0.8cqw solid var(--cyan-light);
  border-radius: 50%;
  background: var(--cyan) no-repeat center / 55%;
  box-shadow: 0 0.9cqw 0 #a9a9a9;
  cursor: pointer;
  z-index: 3;
}
.round:active {
  transform: translateY(0.5cqw);
  box-shadow: 0 0.4cqw 0 #a9a9a9;
}
.round.gear {
  right: 2%;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cpath fill='%23fff' d='M19.14 12.94a7.07 7.07 0 0 0 0-1.88l2.03-1.58a.48.48 0 0 0 .12-.61l-1.92-3.32a.49.49 0 0 0-.59-.22l-2.39.96a7.03 7.03 0 0 0-1.62-.94l-.36-2.54A.48.48 0 0 0 13.93 2h-3.84a.48.48 0 0 0-.48.41l-.36 2.54c-.59.24-1.13.56-1.62.94l-2.39-.96a.49.49 0 0 0-.59.22L2.73 8.47a.47.47 0 0 0 .12.61l2.03 1.58a7.07 7.07 0 0 0 0 1.88l-2.03 1.58a.48.48 0 0 0-.12.61l1.92 3.32c.12.22.37.29.59.22l2.39-.96c.5.38 1.03.7 1.62.94l.36 2.54c.05.24.25.41.48.41h3.84c.24 0 .44-.17.47-.41l.36-2.54c.59-.24 1.13-.56 1.62-.94l2.39.96c.22.08.47 0 .59-.22l1.92-3.32a.48.48 0 0 0-.12-.61l-2.01-1.58zM12 15.6A3.6 3.6 0 1 1 12 8.4a3.6 3.6 0 0 1 0 7.2z'/%3E%3C/svg%3E");
}
.round.menu {
  left: 2%;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cg fill='%23fff'%3E%3Crect x='3' y='4' width='3.2' height='3.2' rx='.8'/%3E%3Crect x='3' y='10.4' width='3.2' height='3.2' rx='.8'/%3E%3Crect x='3' y='16.8' width='3.2' height='3.2' rx='.8'/%3E%3Crect x='8' y='4' width='13' height='3.2' rx='1'/%3E%3Crect x='8' y='10.4' width='13' height='3.2' rx='1'/%3E%3Crect x='8' y='16.8' width='13' height='3.2' rx='1'/%3E%3C/g%3E%3C/svg%3E");
}
.round.backbtn {
  left: 2%;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Cpath fill='%23fff' d='M11.5 3.5 3 12l8.5 8.5V15H21V9h-9.5z'/%3E%3C/svg%3E");
}
.scr-title {
  position: absolute;
  top: 2.6%;
  left: 0;
  right: 0;
  margin: 0;
  text-align: center;
  font: 800 6.6cqw var(--font);
  color: #111;
  letter-spacing: 0.02em;
}

/* Bàn cờ (SVG theo toạ độ 760×900) */
.turn-title text {
  font: 600 48px var(--font);
  fill: #111;
}
.turn-title {
  transition: opacity 0.2s;
}
.turn-title.hide {
  opacity: 0;
}
.cell {
  fill: transparent;
  cursor: pointer;
}
.mark {
  transform-box: fill-box;
  transform-origin: center;
  animation: pop 0.28s cubic-bezier(0.3, 1.6, 0.5, 1);
}
@keyframes pop {
  from {
    transform: scale(0.2);
    opacity: 0;
  }
  to {
    transform: scale(1);
    opacity: 1;
  }
}
.win-line {
  transform-box: fill-box;
  transform-origin: center;
  animation: grow 0.35s ease-out;
}
@keyframes grow {
  from {
    transform: scale(0, 0.6);
  }
}
.score-num {
  font: 600 40px var(--font);
  fill: #111;
}
.score-label {
  font: 800 24px var(--font);
  fill: #111;
}
#underline {
  transition:
    transform 0.3s ease,
    fill 0.3s;
}

/* Dải thông báo ngang màn hình */
.band {
  position: absolute;
  left: 0;
  right: 0;
  top: 41.3%;
  height: 17.3%;
  display: grid;
  place-content: center;
  gap: 1.2cqw;
  background: rgba(40, 40, 40, 0.95);
  color: #fff;
  text-align: center;
  pointer-events: none;
  z-index: 2;
}
.band b {
  font: 700 6.4cqw var(--font);
  line-height: 1.1;
}
.band span {
  font: 700 3.2cqw var(--font);
}
.banner {
  transform: translateX(100%);
}
.banner.show {
  animation: sweep 1.3s cubic-bezier(0.5, 0, 0.5, 1) forwards;
}
@keyframes sweep {
  0% {
    transform: translateX(100%);
  }
  28%,
  72% {
    transform: translateX(0);
  }
  100% {
    transform: translateX(-100%);
  }
}
.result {
  opacity: 0;
  transform: scaleY(0.2);
  transition:
    opacity 0.25s,
    transform 0.25s;
}
.result.show {
  opacity: 1;
  transform: none;
}

/* Ngăn kéo menu / cài đặt */
.shade {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.7);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s;
  z-index: 5;
}
.shade.show {
  opacity: 1;
  pointer-events: auto;
}
.drawer {
  position: absolute;
  top: 0;
  bottom: 0;
  width: 75%;
  background: #333;
  z-index: 6;
  transition: transform 0.28s ease;
}
.drawer.left {
  left: 0;
  transform: translateX(-101%);
}
.drawer.right {
  right: 0;
  transform: translateX(101%);
}
.drawer.open {
  transform: none;
}
.drawer header {
  display: flex;
  height: 11.8cqh;
  height: 14cqw;
  background: #f0f0f0;
}
.drawer h3 {
  flex: 1;
  margin: 0;
  display: grid;
  place-items: center;
  font: 700 6.4cqw var(--font);
  color: #555;
}
.close {
  width: 14cqw;
  border: 0;
  background: #dcdcdc
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24'%3E%3Ccircle cx='12' cy='12' r='9.5' fill='none' stroke='%23444' stroke-width='2.4'/%3E%3Cpath d='M8.5 8.5l7 7M15.5 8.5l-7 7' stroke='%23444' stroke-width='2.6' stroke-linecap='round'/%3E%3C/svg%3E")
    no-repeat center / 62%;
  cursor: pointer;
}
.row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  height: 19.7cqw;
  padding: 0 6.6cqw;
  border: 0;
  border-bottom: 0.3cqw solid #222;
  background: transparent;
  color: #fff;
  font: 700 4.6cqw var(--font);
  text-align: left;
  text-decoration: none;
  cursor: pointer;
}
.row:hover {
  background: #3b3b3b;
}
.switch {
  position: relative;
  width: 19.7cqw;
  height: 8.2cqw;
  border-radius: 1.2cqw;
  background: var(--mint);
  transition: background 0.2s;
}
.switch i {
  position: absolute;
  left: 2.4cqw;
  top: 50%;
  transform: translateY(-50%);
  font: 700 3.6cqw var(--font);
  font-style: normal;
}
.switch::after {
  content: "";
  position: absolute;
  top: 1.2cqw;
  right: 1.2cqw;
  width: 5.8cqw;
  height: 5.8cqw;
  border-radius: 0.8cqw;
  background: #fff;
  transition: right 0.2s;
}
.switch.off {
  background: #777;
}
.switch.off i {
  left: auto;
  right: 2cqw;
}
.switch.off::after {
  right: calc(100% - 7cqw);
}

@media (max-width: 560px) {
  .back {
    position: static;
    margin-bottom: 12px;
  }
  .page {
    align-content: start;
    gap: 0;
  }
}