/* Phong cách Windows 98 cổ điển */
:root {
  --gray: #c0c0c0;
  --light: #ffffff;
  --shadow: #808080;
  --dark: #000000;
  --cell: 26px;
  --ui: "Tahoma", "MS Sans Serif", "Segoe UI", Arial, sans-serif;
}
* {
  box-sizing: border-box;
}
[hidden] {
  display: none !important;
}
html,
body {
  margin: 0;
  min-height: 100%;
}
body {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  padding: 48px 10px 20px;
  background: #008080; /* nền xanh ngọc của Windows 98 */
  font: 12px var(--ui);
  color: #000;
  -webkit-tap-highlight-color: transparent;
}
button {
  font: inherit;
  color: inherit;
}
.back {
  position: fixed;
  top: 12px;
  left: 14px;
  color: #fff;
  font: bold 14px var(--ui);
  text-decoration: none;
  text-shadow: 1px 1px 0 #004040;
}

/* ---------- Cửa sổ ---------- */
.window {
  max-width: 100%;
  padding: 3px;
  background: var(--gray);
  box-shadow:
    inset -1px -1px var(--dark),
    inset 1px 1px #dfdfdf,
    inset -2px -2px var(--shadow),
    inset 2px 2px var(--light),
    4px 4px 0 rgba(0, 0, 0, 0.25);
}
.titlebar {
  display: flex;
  align-items: center;
  gap: 5px;
  height: 22px;
  padding: 0 3px 0 4px;
  background: linear-gradient(90deg, #000080, #1084d0);
  color: #fff;
  font-weight: bold;
  user-select: none;
}
.t-text {
  flex: 1;
  white-space: nowrap;
}
.t-ico {
  width: 16px;
  height: 16px;
  background: radial-gradient(circle at 40% 40%, #fff 0 10%, #000 12% 55%, transparent 57%);
}
.t-btn {
  width: 18px;
  height: 16px;
  display: grid;
  place-items: center;
  padding: 0;
  border: 0;
  background: var(--gray);
  color: #000;
  font: bold 11px var(--ui);
  text-decoration: none;
  cursor: pointer;
  box-shadow:
    inset -1px -1px var(--dark),
    inset 1px 1px var(--light),
    inset -2px -2px var(--shadow);
}
.t-btn:active {
  box-shadow:
    inset 1px 1px var(--dark),
    inset -1px -1px var(--light),
    inset 2px 2px var(--shadow);
}

/* ---------- Menu ---------- */
.menubar {
  display: flex;
  height: 20px;
  margin-top: 1px;
  user-select: none;
}
.menu {
  position: relative;
}
.m-top {
  height: 20px;
  padding: 0 7px;
  border: 0;
  background: none;
  cursor: pointer;
}
.m-top.open,
.m-top:hover {
  background: #000080;
  color: #fff;
}
.m-list {
  position: absolute;
  top: 20px;
  left: 0;
  z-index: 20;
  min-width: 170px;
  padding: 2px;
  background: var(--gray);
  box-shadow:
    inset -1px -1px var(--dark),
    inset 1px 1px #dfdfdf,
    inset -2px -2px var(--shadow),
    inset 2px 2px var(--light),
    2px 2px 0 rgba(0, 0, 0, 0.3);
}
.m-list button {
  display: flex;
  width: 100%;
  padding: 3px 18px 3px 20px;
  border: 0;
  background: none;
  text-align: left;
  cursor: pointer;
  position: relative;
}
.m-list button:hover {
  background: #000080;
  color: #fff;
}
.m-list button.on::before {
  content: "✓";
  position: absolute;
  left: 6px;
}
.m-list kbd {
  margin-left: auto;
  padding-left: 18px;
  font: inherit;
}
.m-list hr {
  margin: 3px 1px;
  border: 0;
  border-top: 1px solid var(--shadow);
  border-bottom: 1px solid var(--light);
}

/* ---------- Thân ---------- */
.body {
  padding: 6px;
  border-left: 3px solid var(--light);
  border-top: 3px solid var(--light);
  margin-top: 2px;
}
.sunken {
  border: 3px solid;
  border-color: var(--shadow) var(--light) var(--light) var(--shadow);
}
.panel.top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 4px 5px;
  margin-bottom: 6px;
  border-width: 2px;
}
.led {
  display: flex;
  gap: 1px;
  height: 29px;
  padding: 1px;
  background: #000;
  border: 1px solid;
  border-color: var(--shadow) var(--light) var(--light) var(--shadow);
}
.led svg {
  width: 15px;
  height: 27px;
}
.led .on {
  fill: #ff0000;
}
.led .off {
  fill: #2a0000;
}
.face {
  width: 28px;
  height: 28px;
  padding: 0;
  border: 1px solid var(--shadow);
  background: var(--gray);
  cursor: pointer;
  box-shadow:
    inset -2px -2px var(--shadow),
    inset 2px 2px var(--light);
}
.face.down {
  box-shadow: inset 2px 2px var(--shadow);
}
.face svg {
  display: block;
  width: 22px;
  height: 22px;
  margin: auto;
}
.face.down svg {
  transform: translate(1px, 1px);
}

/* ---------- Bãi mìn ---------- */
.field-scroll {
  max-width: calc(100vw - 40px);
  overflow-x: auto;
}
.field {
  display: grid;
  grid-template-columns: repeat(var(--cols), var(--cell));
  grid-auto-rows: var(--cell);
  width: max-content;
  user-select: none;
  -webkit-user-select: none;
  touch-action: manipulation;
}
.c {
  display: grid;
  place-items: center;
  background: var(--gray);
  font: bold calc(var(--cell) * 0.62) / 1 "Courier New", var(--ui);
  cursor: default;
  box-shadow:
    inset -2px -2px var(--shadow),
    inset 2px 2px var(--light);
}
.c.open,
.c.press {
  box-shadow: none;
  border-left: 1px solid var(--shadow);
  border-top: 1px solid var(--shadow);
}
.c.boom {
  background: #ff0000;
}
.c svg {
  width: 72%;
  height: 72%;
  pointer-events: none;
}
.c.q::after {
  content: "?";
  font-family: var(--ui);
}
.n1 {
  color: #0000ff;
}
.n2 {
  color: #008000;
}
.n3 {
  color: #ff0000;
}
.n4 {
  color: #000080;
}
.n5 {
  color: #800000;
}
.n6 {
  color: #008080;
}
.n7 {
  color: #000000;
}
.n8 {
  color: #808080;
}

/* ---------- Thanh cảm ứng ---------- */
.touchbar {
  display: none;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  color: #e0ffff;
}
@media (pointer: coarse) {
  .touchbar {
    display: flex;
  }
}
#btnFlagMode {
  color: #000;
  display: flex;
  align-items: center;
  gap: 6px;
  height: 34px;
  padding: 0 14px;
  border: 0;
  background: var(--gray);
  font-weight: bold;
  box-shadow:
    inset -1px -1px var(--dark),
    inset 1px 1px var(--light),
    inset -2px -2px var(--shadow),
    inset 2px 2px #dfdfdf;
}
#btnFlagMode[aria-pressed="true"] {
  box-shadow:
    inset 1px 1px var(--dark),
    inset -1px -1px var(--light),
    inset 2px 2px var(--shadow);
  background: #d8d8d8;
}
.mini-flag {
  width: 14px;
  height: 14px;
  background: linear-gradient(135deg, #ff0000 0 50%, transparent 50%) 0 0 / 9px 8px no-repeat,
    linear-gradient(#000, #000) 7px 0 / 2px 14px no-repeat;
}

/* ---------- Hộp thoại ---------- */
.dlg-wrap {
  position: fixed;
  inset: 0;
  z-index: 50;
  display: grid;
  place-items: center;
  background: rgba(0, 0, 0, 0.15);
}
.dlg {
  width: min(300px, 92vw);
}
.dlg-body {
  padding: 14px 12px 12px;
  line-height: 1.6;
}
.dlg-body table {
  border-collapse: collapse;
  margin: 0 auto 12px;
}
.dlg-body td {
  padding: 3px 8px;
}
.dlg-body input {
  width: 64px;
  padding: 2px 4px;
  border: 2px solid;
  border-color: var(--shadow) var(--light) var(--light) var(--shadow);
  font: inherit;
}
.dlg-btns {
  display: flex;
  justify-content: center;
  gap: 8px;
}
.btn98 {
  min-width: 76px;
  height: 24px;
  border: 0;
  background: var(--gray);
  cursor: pointer;
  box-shadow:
    inset -1px -1px var(--dark),
    inset 1px 1px var(--light),
    inset -2px -2px var(--shadow),
    inset 2px 2px #dfdfdf;
}
.btn98:active {
  box-shadow:
    inset 1px 1px var(--dark),
    inset -1px -1px var(--light),
    inset 2px 2px var(--shadow);
}
.btn98:focus-visible {
  outline: 1px dotted #000;
  outline-offset: -5px;
}