/*!
 * 四子棋在线对战 · connect-four
 * 独立设计系统「儿童积木」：天蓝底板 + 柠檬黄 + 珊瑚红 + 深蓝描边
 * 字体层级：圆润粗黑标题 + 等宽手数；棋盘是真实圆孔立板
 */
.cf4-page, .cf4-modal, .cf4-toast {
    --cf4-bg: #eaf5fb;
    --cf4-card: #ffffff;
    --cf4-card2: #f2f9fd;
    --cf4-line: #cde3f0;
    --cf4-ink: #173b55;
    --cf4-ink2: #64839a;
    --cf4-blue: #2179b5;
    --cf4-board: #2a7fc4;
    --cf4-red: #ff6f61;
    --cf4-yellow: #ffd447;
    --cf4-soft: rgba(33, 121, 181, .1);
    --cf4-num: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
}
:root[data-theme="dark"] .cf4-page, :root[data-theme="dark"] .cf4-modal, :root[data-theme="dark"] .cf4-toast {
    --cf4-bg: #0e1922;
    --cf4-card: #172633;
    --cf4-card2: #1e303f;
    --cf4-line: #2e485b;
    --cf4-ink: #e8f4fb;
    --cf4-ink2: #9db7c8;
    --cf4-blue: #66b6ea;
    --cf4-board: #1d4a70;
    --cf4-red: #ff8f80;
    --cf4-yellow: #ffdf70;
    --cf4-soft: rgba(102, 182, 234, .13);
}
.cf4-page { background: var(--cf4-bg); color: var(--cf4-ink); font-family: "PingFang SC", "Microsoft YaHei", system-ui, sans-serif; font-size: 15px; line-height: 1.75; }
.cf4-page *, .cf4-page *::before, .cf4-page *::after { box-sizing: border-box; }
.cf4-wrap { max-width: 1120px; margin: 0 auto; padding: 20px 16px 12px; }
.cf4-page .detail-breadcrumb { margin: 0 0 16px; font-size: 13px; color: var(--cf4-ink2); }
.cf4-page .detail-breadcrumb a { color: var(--cf4-blue); text-decoration: none; }
.cf4-page .detail-breadcrumb .sep { margin: 0 8px; opacity: .6; }

/* ---------- Hero ---------- */
.cf4-hero { display: grid; grid-template-columns: minmax(0, 1.05fr) minmax(0, .95fr); gap: 22px; align-items: center; padding: 26px 30px; border-radius: 28px; border: 2px solid var(--cf4-line); background: radial-gradient(90% 120% at 100% 0, rgba(255, 212, 71, .25), transparent 60%), var(--cf4-card); }
.cf4-kicker { display: inline-block; padding: 5px 12px; border-radius: 999px; background: var(--cf4-soft); color: var(--cf4-blue); font: 800 11px var(--cf4-num); letter-spacing: .14em; }
.cf4-hero h1 { margin: 12px 0 6px; font-size: clamp(29px, 3.5vw, 42px); line-height: 1.18; font-weight: 900; letter-spacing: .01em; }
.cf4-sub { margin: 0 0 18px; color: var(--cf4-ink2); font-size: 15px; }
.cf4-sub b { color: var(--cf4-blue); }
.cf4-hero-actions { display: flex; gap: 10px; flex-wrap: wrap; }
.cf4-cta { cursor: pointer; border: 0; border-radius: 999px; padding: 12px 26px; font-size: 15px; font-weight: 900; color: #173b55; background: var(--cf4-yellow); box-shadow: 0 8px 0 #d9aa20, 0 14px 22px -12px rgba(23, 59, 85, .8); transition: transform .14s, box-shadow .14s; }
.cf4-cta:hover { transform: translateY(-2px); box-shadow: 0 10px 0 #d9aa20, 0 16px 24px -12px rgba(23, 59, 85, .8); }
.cf4-ghost, .cf4-mini { cursor: pointer; border: 2px solid var(--cf4-line); border-radius: 999px; background: var(--cf4-card); color: var(--cf4-ink); font-size: 13px; font-weight: 800; padding: 10px 18px; }
.cf4-mini { border-radius: 10px; padding: 8px 12px; font-size: 12px; }
.cf4-mini:disabled { opacity: .45; cursor: not-allowed; }
.cf4-mini-solid { background: var(--cf4-blue); color: #fff; border-color: var(--cf4-blue); }
.cf4-ghost:hover, .cf4-mini:hover:not(:disabled) { border-color: var(--cf4-blue); }
.cf4-hero-note { margin: 14px 0 0; font-size: 12px; color: var(--cf4-ink2); }
.cf4-hero-board { justify-self: center; display: grid; grid-template-columns: repeat(7, 30px); gap: 6px; padding: 14px; border-radius: 16px; background: var(--cf4-board); box-shadow: 0 12px 22px -14px rgba(23, 59, 85, .9), inset 0 -6px 0 rgba(0,0,0,.15); transform: rotate(-3deg); }
.cf4-hero-board span { width: 30px; height: 30px; border-radius: 50%; background: var(--cf4-card2); box-shadow: inset 0 3px 5px rgba(0,0,0,.25); }
.cf4-hero-board span.r { background: var(--cf4-red); }
.cf4-hero-board span.y { background: var(--cf4-yellow); }

/* ---------- 面板 ---------- */
.cf4-panel { margin-top: 18px; border: 2px solid var(--cf4-line); border-radius: 22px; background: var(--cf4-card); overflow: hidden; }
.cf4-topbar { display: grid; grid-template-columns: repeat(4, 1fr); border-bottom: 2px solid var(--cf4-line); background: var(--cf4-soft); }
.cf4-metric { padding: 11px 15px; border-right: 1px dashed var(--cf4-line); }
.cf4-metric:last-child { border-right: 0; }
.cf4-metric span { display: block; font-size: 11px; color: var(--cf4-ink2); }
.cf4-metric b { font: 900 19px var(--cf4-num); color: var(--cf4-blue); }
.cf4-main { display: grid; grid-template-columns: minmax(0, 1fr) 300px; }
.cf4-board-area { min-width: 0; padding: 18px; }
.cf4-board-head { display: flex; justify-content: space-between; gap: 10px; margin-bottom: 10px; font-size: 13px; color: var(--cf4-ink2); }
.cf4-board-head b { color: var(--cf4-ink); }
.cf4-drop-row { display: grid; gap: 7px; margin-bottom: 7px; }
.cf4-drop { border: 0; cursor: pointer; border-radius: 999px; height: 30px; background: var(--cf4-yellow); color: #173b55; font: 900 13px var(--cf4-num); box-shadow: 0 3px 0 #d9aa20; }
.cf4-drop:hover:not(:disabled) { filter: brightness(1.06); }
.cf4-drop:disabled { background: var(--cf4-card2); color: var(--cf4-ink2); box-shadow: none; cursor: not-allowed; }
.cf4-board { display: grid; gap: 7px; padding: 14px; border-radius: 18px; background: var(--cf4-board); box-shadow: inset 0 -7px 0 rgba(0,0,0,.16); }
.cf4-hole { width: 100%; aspect-ratio: 1; border-radius: 50%; background: var(--cf4-card2); box-shadow: inset 0 4px 7px rgba(0,0,0,.25); }
.cf4-hole.p1 { background: var(--cf4-red); box-shadow: inset 0 -5px 0 rgba(0,0,0,.16); }
.cf4-hole.p2 { background: var(--cf4-yellow); box-shadow: inset 0 -5px 0 rgba(0,0,0,.16); }
.cf4-hole.win { outline: 4px solid #fff; outline-offset: 2px; }

/* ---------- 侧栏 ---------- */
.cf4-side { min-width: 0; padding: 18px; border-left: 2px solid var(--cf4-line); background: var(--cf4-card2); }
.cf4-side-title { margin: 0 0 10px; font-size: 14px; font-weight: 900; color: var(--cf4-blue); }
.cf4-side-title:not(:first-child) { margin-top: 20px; }
.cf4-l { display: block; margin: 8px 0 4px; font-size: 12px; color: var(--cf4-ink2); }
.cf4-input { width: 100%; min-width: 0; border: 2px solid var(--cf4-line); border-radius: 10px; padding: 8px 9px; background: var(--cf4-card); color: var(--cf4-ink); font: 13px inherit; }
.cf4-input:focus { outline: 2px solid var(--cf4-blue); outline-offset: 1px; }
.cf4-dims { display: grid; grid-template-columns: 1fr 1fr; gap: 8px; }
.cf4-validate { min-height: 20px; margin: 7px 0 0; font-size: 12px; color: var(--cf4-red); }
.cf4-row { display: flex; gap: 7px; margin-top: 9px; flex-wrap: wrap; }
.cf4-inline { display: flex; gap: 7px; }
.cf4-inline .cf4-input { flex: 1; }
.cf4-log { margin: 0; padding-left: 20px; max-height: 140px; overflow: auto; font: 12px/1.9 var(--cf4-num); color: var(--cf4-ink2); }

/* ---------- 实验室 ---------- */
.cf4-lab { margin-top: 18px; padding: 22px; border: 2px solid var(--cf4-line); border-radius: 22px; background: var(--cf4-card); }
.cf4-lab-head h2 { margin: 0 0 4px; font-size: 19px; }
.cf4-lab-head p { margin: 0 0 16px; font-size: 13px; color: var(--cf4-ink2); }
.cf4-lab-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.cf4-lab-box { min-width: 0; padding: 16px; border: 2px dashed var(--cf4-line); border-radius: 16px; background: var(--cf4-card2); }
.cf4-lab-box label { display: block; margin-bottom: 8px; font-size: 12px; font-weight: 800; }
.cf4-batch { margin-top: 10px; font: 12px/1.9 var(--cf4-num); white-space: pre-wrap; color: var(--cf4-blue); }
.cf4-rulelist { font: 12px/2 var(--cf4-num); }
.cf4-rulelist div { display: flex; justify-content: space-between; border-bottom: 1px dotted var(--cf4-line); }
.cf4-lab-note { margin: 10px 0 0; font-size: 12px; color: var(--cf4-ink2); }
.cf4-lab-note code { font-family: var(--cf4-num); background: var(--cf4-soft); padding: 1px 4px; }

/* ---------- 弹窗 / toast ---------- */
.cf4-modal { position: fixed; inset: 0; z-index: 9000; display: flex; align-items: center; justify-content: center; padding: 20px; background: rgba(12, 40, 60, .55); }
.cf4-modal[hidden] { display: none !important; }
.cf4-modal-box { position: relative; width: min(410px, 100%); padding: 30px; border: 3px solid var(--cf4-yellow); border-radius: 26px; background: var(--cf4-card); text-align: center; }
.cf4-modal-x { position: absolute; right: 14px; top: 8px; border: 0; background: transparent; font-size: 26px; color: var(--cf4-ink2); cursor: pointer; }
.cf4-modal-badge { font: 900 11px var(--cf4-num); letter-spacing: .18em; color: var(--cf4-blue); }
.cf4-modal-box h2 { margin: 10px 0 6px; font-size: 25px; }
.cf4-modal-box p { margin: 0 0 14px; color: var(--cf4-ink2); font-size: 13px; }
.cf4-modal-stats { display: grid; grid-template-columns: repeat(3, 1fr); gap: 8px; margin-bottom: 18px; font: 12px var(--cf4-num); }
.cf4-modal-stats div { padding: 9px 2px; border-radius: 12px; background: var(--cf4-card2); }
.cf4-modal-stats b { display: block; font-size: 18px; color: var(--cf4-red); }
.cf4-toast { position: fixed; left: 50%; bottom: 30px; transform: translateX(-50%); z-index: 9500; padding: 10px 18px; border-radius: 999px; background: var(--cf4-ink); color: var(--cf4-card); font-size: 13px; opacity: 0; pointer-events: none; transition: opacity .25s; }
.cf4-toast.on { opacity: 1; }

@media (max-width: 940px) {
    .cf4-hero { grid-template-columns: 1fr; }
    .cf4-hero-board { display: none; }
    .cf4-main { grid-template-columns: 1fr; }
    .cf4-side { border-left: 0; border-top: 2px solid var(--cf4-line); }
    .cf4-lab-grid { grid-template-columns: 1fr; }
}
@media (max-width: 560px) {
    .cf4-topbar { grid-template-columns: repeat(2, 1fr); }
    .cf4-metric:nth-child(2) { border-right: 0; }
    .cf4-board { gap: 4px; padding: 9px; }
    .cf4-drop-row { gap: 4px; }
    .cf4-hero h1 { font-size: 29px; }
}