/* 练习题：题库列表 + 做题页。颜色变量来自 ../assets/site.css（亮色 / 暗色） */
:root {
  --easy: #00a870; --medium: #e8a100; --hard: #ff375f;
  --ok: #28a745; --bad: #ff3b30; --warn: #e8a100;
  --code-bg: #f6f7f9; --panel: var(--surface); --hover: rgba(127, 127, 127, 0.08);
}
:root[data-theme="dark"] { --code-bg: #17171a; --easy: #2fd08f; --medium: #ffc233; --hard: #ff6b81; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) { --code-bg: #17171a; --easy: #2fd08f; --medium: #ffc233; --hard: #ff6b81; } }

body { background: var(--bg); }
.wrap.wide { max-width: none; padding: 0 20px; }
.loading-page { padding: 120px 20px; text-align: center; color: var(--muted); }
button { font: inherit; }
kbd { font: 12px/1 ui-monospace, SFMono-Regular, Menlo, monospace; padding: 2px 5px; border: 1px solid var(--line); border-bottom-width: 2px; border-radius: 5px; color: var(--muted); }

/* ---------- 列表页 ---------- */
.list-page { max-width: 1120px; margin: 0 auto; padding: 36px 24px 80px; }
.intro { display: flex; flex-wrap: wrap; align-items: flex-end; justify-content: space-between; gap: 24px; margin-bottom: 26px; }
.intro h1 { margin: 0 0 8px; font-size: 32px; letter-spacing: -0.02em; }
.intro p { margin: 0; max-width: 46em; color: var(--muted); font-size: 15px; }
.intro p a { color: var(--blue); }
.stats { display: flex; gap: 10px; flex-wrap: wrap; }
.stat { min-width: 92px; padding: 10px 14px; background: var(--surface); border: 1px solid var(--line); border-radius: 12px; }
.stat b { display: block; font-size: 22px; letter-spacing: -0.02em; line-height: 1.2; }
.stat span { font-size: 12px; color: var(--muted); }
.stat.easy b { color: var(--easy); } .stat.medium b { color: var(--medium); } .stat.hard b { color: var(--hard); }

.filters {
  position: sticky; top: 60px; z-index: 5; display: flex; flex-wrap: wrap; gap: 10px; align-items: center;
  padding: 12px 0; margin-bottom: 8px; background: color-mix(in srgb, var(--bg) 90%, transparent);
  -webkit-backdrop-filter: blur(12px); backdrop-filter: blur(12px); border-bottom: 1px solid var(--line);
}
.seg { display: inline-flex; padding: 3px; gap: 2px; background: rgba(127, 127, 127, 0.1); border-radius: 10px; flex-wrap: wrap; }
.seg button { border: 0; background: transparent; color: var(--muted); font-size: 13.5px; padding: 5px 12px; border-radius: 7px; cursor: pointer; white-space: nowrap; }
.seg button:hover { color: var(--fg); }
.seg button.on { background: var(--surface); color: var(--fg); font-weight: 600; box-shadow: 0 1px 3px rgba(0, 0, 0, 0.12); }
.filters select, .filters input {
  height: 34px; padding: 0 10px; border: 1px solid var(--line); border-radius: 9px; background: var(--surface); color: var(--fg); font-size: 13.5px;
}
.filters input { flex: 1; min-width: 160px; }
.filters .count { font-size: 13px; color: var(--faint); margin-left: auto; }

.book-h { display: flex; align-items: baseline; gap: 10px; margin: 34px 0 6px; }
.book-h h2 { margin: 0; font-size: 20px; }
.book-h span { font-size: 13px; color: var(--faint); }
.chap { margin-top: 14px; border: 1px solid var(--line); border-radius: 12px; overflow: hidden; background: var(--surface); }
.chap-h { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding: 9px 14px; font-size: 13px; color: var(--muted); background: rgba(127, 127, 127, 0.05); border-bottom: 1px solid var(--line); }
.chap-h b { color: var(--text); font-weight: 600; }
.chap-h a { color: var(--blue); white-space: nowrap; }
.row { display: grid; grid-template-columns: 26px 46px 1fr auto 64px; align-items: center; gap: 10px; padding: 10px 14px; font-size: 14.5px; cursor: pointer; }
.row + .row { border-top: 1px solid var(--line); }
.row:hover { background: var(--hover); }
.row .num { color: var(--faint); font-variant-numeric: tabular-nums; }
.row .ttl { color: var(--fg); font-weight: 500; }
.row .tags { display: flex; gap: 6px; flex-wrap: wrap; justify-content: flex-end; }
.tag { font-size: 12px; padding: 1px 8px; border-radius: 999px; background: rgba(127, 127, 127, 0.1); color: var(--muted); white-space: nowrap; }
.tag.env { background: color-mix(in srgb, var(--purple) 14%, transparent); color: var(--purple); }
.tag.env.cuda { background: color-mix(in srgb, var(--ok) 14%, transparent); color: var(--ok); }
.tag.env.cpp { background: color-mix(in srgb, var(--blue) 14%, transparent); color: var(--blue); }
.diff { font-size: 13px; font-weight: 600; text-align: right; }
.diff.d1 { color: var(--easy); } .diff.d2 { color: var(--medium); } .diff.d3 { color: var(--hard); }
.st { width: 18px; height: 18px; display: inline-flex; align-items: center; justify-content: center; }
.st svg { width: 18px; height: 18px; }
.st.solved { color: var(--ok); } .st.tried { color: var(--warn); }
.empty { padding: 60px 0; text-align: center; color: var(--muted); }
.local-box { margin-top: 44px; padding: 18px 20px; border: 1px dashed var(--line); border-radius: 12px; color: var(--muted); font-size: 14px; }
.local-box h3 { margin: 0 0 8px; color: var(--fg); font-size: 15px; }
.local-box code, .md code { font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; font-size: .9em; }

/* ---------- 做题页 ---------- */
.ws { display: flex; height: calc(100vh - 61px); height: calc(100dvh - 61px); }
.pane { min-width: 0; display: flex; flex-direction: column; background: var(--surface); }
.pane.left { flex: 0 0 44%; border-right: 1px solid var(--line); }
.pane.right { flex: 1; }
.splitter { flex: 0 0 5px; margin: 0 -3px; cursor: col-resize; z-index: 2; }
.splitter:hover, .splitter.drag { background: color-mix(in srgb, var(--blue) 35%, transparent); }
.ptabs { display: flex; align-items: center; gap: 2px; padding: 0 10px; height: 42px; border-bottom: 1px solid var(--line); flex: none; }
.ptabs button { border: 0; background: transparent; color: var(--muted); font-size: 13.5px; padding: 6px 11px; border-radius: 7px; cursor: pointer; }
.ptabs button:hover { color: var(--fg); background: var(--hover); }
.ptabs button.on { color: var(--fg); font-weight: 600; }
.ptabs .grow { flex: 1; }
.ptabs a.navbtn { font-size: 13px; color: var(--muted); padding: 5px 8px; border-radius: 7px; }
.ptabs a.navbtn:hover { color: var(--fg); background: var(--hover); }
.scroll { flex: 1; overflow: auto; padding: 18px 22px 40px; }
.ph h1 { margin: 0 0 10px; font-size: 22px; letter-spacing: -0.01em; }
.meta { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; margin-bottom: 16px; font-size: 13px; }
.meta .diff { text-align: left; }
.meta a { color: var(--blue); }
.md { font-size: 15px; line-height: 1.75; color: var(--text); }
.md h2, .md h3 { color: var(--fg); margin: 1.4em 0 .6em; font-size: 16px; }
.md p { margin: .7em 0; }
.md ul, .md ol { padding-left: 1.4em; }
.md li { margin: .25em 0; }
.md :not(pre) > code { padding: .1em .35em; border-radius: 5px; background: var(--code-bg); color: var(--fg); }
.md pre { margin: .9em 0; padding: 12px 14px; border-radius: 10px; background: var(--code-bg); overflow: auto; font-size: 13.5px; line-height: 1.55; }
.md pre code.hljs { padding: 0; background: transparent; }
.md table { border-collapse: collapse; margin: .8em 0; font-size: 14px; }
.md th, .md td { border: 1px solid var(--line); padding: 5px 10px; }
.md blockquote { margin: .8em 0; padding: 2px 14px; border-left: 3px solid var(--line); color: var(--muted); }
.md .katex-display { overflow-x: auto; overflow-y: hidden; }
.note { margin: 14px 0; padding: 12px 14px; border-radius: 10px; font-size: 14px; background: color-mix(in srgb, var(--blue) 8%, transparent); border: 1px solid color-mix(in srgb, var(--blue) 25%, transparent); color: var(--text); }
.note.warn { background: color-mix(in srgb, var(--warn) 10%, transparent); border-color: color-mix(in srgb, var(--warn) 35%, transparent); }
.reveal { margin: 30px 0; text-align: center; color: var(--muted); font-size: 14px; }
.btn { display: inline-flex; align-items: center; gap: 6px; height: 32px; padding: 0 14px; border-radius: 8px; border: 1px solid var(--line); background: var(--surface); color: var(--fg); font-size: 13.5px; cursor: pointer; white-space: nowrap; }
.btn:hover { background: var(--hover); }
.btn:disabled { opacity: .5; cursor: not-allowed; }
.btn.primary { background: var(--ok); border-color: var(--ok); color: #fff; font-weight: 600; }
.btn.primary:hover { filter: brightness(1.06); }
.btn.run { font-weight: 600; }
.btn svg { width: 15px; height: 15px; }

.edbar { display: flex; align-items: center; gap: 8px; padding: 0 10px; height: 42px; border-bottom: 1px solid var(--line); flex: none; }
.edbar .lang { font-size: 13px; color: var(--muted); }
.edbar .grow { flex: 1; }
.pystatus { font-size: 12.5px; color: var(--faint); display: inline-flex; align-items: center; gap: 6px; }
.pystatus i { width: 7px; height: 7px; border-radius: 50%; background: var(--faint); }
.pystatus.ready i { background: var(--ok); } .pystatus.busy i { background: var(--warn); animation: pulse 1s infinite; }
@keyframes pulse { 50% { opacity: .3; } }
.editor { flex: 1 1 60%; min-height: 120px; position: relative; }
.editor .CodeMirror { position: absolute; inset: 0; height: auto; font: 13.5px/1.6 "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; background: var(--surface); color: var(--fg); }
.CodeMirror-gutters { background: var(--surface); border-right: 1px solid var(--line); }
.CodeMirror-linenumber { color: var(--faint); }
.CodeMirror-cursor { border-left-color: var(--fg); }
.CodeMirror-activeline-background { background: var(--hover); }
.CodeMirror-selected { background: color-mix(in srgb, var(--blue) 18%, transparent) !important; }
.CodeMirror-matchingbracket { color: var(--ok) !important; text-decoration: underline; }
:root[data-theme="dark"] .cm-s-default .cm-keyword { color: #ff7ab2; }
:root[data-theme="dark"] .cm-s-default .cm-def { color: #6bdfff; }
:root[data-theme="dark"] .cm-s-default .cm-variable-2, :root[data-theme="dark"] .cm-s-default .cm-variable { color: #e6e6e6; }
:root[data-theme="dark"] .cm-s-default .cm-string { color: #ff8170; }
:root[data-theme="dark"] .cm-s-default .cm-number { color: #d9c97c; }
:root[data-theme="dark"] .cm-s-default .cm-comment { color: #7f8c98; }
:root[data-theme="dark"] .cm-s-default .cm-builtin { color: #dabaff; }
:root[data-theme="dark"] .cm-s-default .cm-operator { color: #e6e6e6; }
:root[data-theme="dark"] .cm-s-default .cm-property { color: #9ef0f0; }
:root[data-theme="dark"] .cm-s-default .cm-meta { color: #fd8f3f; }
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) .cm-s-default .cm-keyword { color: #ff7ab2; }
  :root:not([data-theme="light"]) .cm-s-default .cm-def { color: #6bdfff; }
  :root:not([data-theme="light"]) .cm-s-default .cm-variable-2, :root:not([data-theme="light"]) .cm-s-default .cm-variable { color: #e6e6e6; }
  :root:not([data-theme="light"]) .cm-s-default .cm-string { color: #ff8170; }
  :root:not([data-theme="light"]) .cm-s-default .cm-number { color: #d9c97c; }
  :root:not([data-theme="light"]) .cm-s-default .cm-comment { color: #7f8c98; }
  :root:not([data-theme="light"]) .cm-s-default .cm-builtin { color: #dabaff; }
  :root:not([data-theme="light"]) .cm-s-default .cm-operator { color: #e6e6e6; }
  :root:not([data-theme="light"]) .cm-s-default .cm-property { color: #9ef0f0; }
  :root:not([data-theme="light"]) .cm-s-default .cm-meta { color: #fd8f3f; }
}

.hsplit { flex: 0 0 5px; margin: -3px 0; cursor: row-resize; z-index: 2; }
.hsplit:hover, .hsplit.drag { background: color-mix(in srgb, var(--blue) 35%, transparent); }
.console { flex: 0 0 38%; min-height: 80px; display: flex; flex-direction: column; border-top: 1px solid var(--line); }
.console .scroll { padding: 14px 16px 30px; }
.verdict { display: flex; align-items: baseline; gap: 12px; margin-bottom: 12px; }
.verdict b { font-size: 19px; }
.verdict.accepted b { color: var(--ok); } .verdict.bad b { color: var(--bad); } .verdict.timeout b { color: var(--warn); }
.verdict span { font-size: 13px; color: var(--muted); }
.cases { display: flex; flex-direction: column; gap: 8px; }
.case { border: 1px solid var(--line); border-radius: 9px; overflow: hidden; }
.case-h { display: flex; align-items: center; gap: 8px; padding: 7px 11px; font-size: 13.5px; cursor: pointer; }
.case-h .mk { font-weight: 700; width: 14px; }
.case.pass .mk { color: var(--ok); } .case.fail .mk, .case.error .mk { color: var(--bad); } .case.skip .mk { color: var(--warn); }
.case-h .nm { font-family: ui-monospace, SFMono-Regular, Menlo, monospace; font-size: 12.5px; }
.case-h .dc { color: var(--muted); flex: 1; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.case-h .ms { color: var(--faint); font-size: 12px; }
.case-b { display: none; padding: 0 11px 10px; }
.case.open .case-b { display: block; }
pre.out { margin: 6px 0 0; padding: 10px 12px; border-radius: 8px; background: var(--code-bg); color: var(--text); font: 12.5px/1.55 ui-monospace, SFMono-Regular, Menlo, monospace; white-space: pre-wrap; word-break: break-word; }
pre.out.err { color: var(--bad); }
.hint { color: var(--faint); font-size: 13px; }
.subs { width: 100%; border-collapse: collapse; font-size: 13.5px; }
.subs td, .subs th { padding: 8px 6px; border-bottom: 1px solid var(--line); text-align: left; }
.subs th { color: var(--muted); font-weight: 500; }
.subs .ok { color: var(--ok); font-weight: 600; } .subs .no { color: var(--bad); font-weight: 600; }
.cmd { position: relative; }
.cmd pre { padding-right: 60px; }

@media (max-width: 900px) {
  html, body { overflow-x: hidden; }
  .ws { flex-direction: column; height: auto; }
  .ptabs { overflow-x: auto; scrollbar-width: none; }
  .ptabs::-webkit-scrollbar { display: none; }
  .ptabs button, .ptabs a.navbtn { flex: none; }
  .edbar { flex-wrap: wrap; height: auto; padding: 8px 10px; row-gap: 6px; }
  .edbar .lang { display: none; }
  .pystatus span { max-width: 44vw; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
  .scroll { padding: 16px 16px 30px; }
  .pane.left { flex: none; border-right: 0; border-bottom: 1px solid var(--line); }
  .pane.left .scroll { max-height: none; }
  .splitter, .hsplit { display: none; }
  .editor { height: 60vh; flex: none; }
  .console { flex: none; min-height: 200px; }
  .row { grid-template-columns: 22px 38px 1fr 48px; }
  .row .tags { display: none; }
  .list-page { padding: 24px 16px 60px; }
}

/* ---------- 代码补全、函数签名、语法错误 ---------- */
.CodeMirror-hints {
  z-index: 50; padding: 4px; border: 1px solid var(--line); border-radius: 10px; background: var(--surface); color: var(--fg);
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.16); font: 13px/1.5 "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; max-height: 16em;
}
.CodeMirror-hint { display: flex; align-items: center; gap: 8px; padding: 2px 8px 2px 4px; border-radius: 6px; color: var(--fg); white-space: nowrap; }
li.CodeMirror-hint-active { background: color-mix(in srgb, var(--blue) 16%, transparent); color: var(--fg); }
.hi-ic { flex: none; width: 17px; height: 17px; border-radius: 4px; display: inline-grid; place-items: center; font-size: 11px; font-weight: 700;
  color: var(--muted); background: rgba(127, 127, 127, 0.14); }
.hi-ic.t-function { color: #a45cff; background: color-mix(in srgb, #a45cff 16%, transparent); }
.hi-ic.t-class { color: #e8a100; background: color-mix(in srgb, #e8a100 16%, transparent); }
.hi-ic.t-module { color: var(--blue); background: color-mix(in srgb, var(--blue) 16%, transparent); }
.hi-ic.t-instance, .hi-ic.t-statement, .hi-ic.t-param, .hi-ic.t-word { color: #0aa5a5; background: color-mix(in srgb, #0aa5a5 16%, transparent); }
.hi-ic.t-keyword, .hi-ic.t-std { color: #ff375f; background: color-mix(in srgb, #ff375f 14%, transparent); }
.hi-nm { flex: 1; }
.hi-ty { margin-left: 18px; font: 11.5px/1 -apple-system, BlinkMacSystemFont, "PingFang SC", sans-serif; color: var(--faint); }
.hint-doc, .sig-tip {
  position: fixed; z-index: 51; max-width: min(520px, calc(100vw - 16px)); padding: 8px 11px; border: 1px solid var(--line); border-radius: 10px;
  background: var(--surface); color: var(--text); box-shadow: 0 10px 30px rgba(0, 0, 0, 0.16); font-size: 12.5px; line-height: 1.55;
}
.hint-doc[hidden], .sig-tip[hidden] { display: none; }
.hint-doc code, .sig-tip code { display: block; font: 12.5px/1.5 "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace; color: var(--fg); white-space: pre-wrap; word-break: break-word; }
.hint-doc code + code { margin-top: 2px; }
.hint-doc p, .sig-tip p { margin: 6px 0 0; color: var(--muted); white-space: pre-wrap; display: -webkit-box; -webkit-box-orient: vertical; -webkit-line-clamp: 8; overflow: hidden; }
.sig-tip p { -webkit-line-clamp: 3; }
.sig-tip b { color: var(--blue); font-weight: 700; }
.sig-tip .more, .hint-doc .more { font-size: 11.5px; color: var(--faint); }
.cm-lint-err { text-decoration: underline wavy var(--bad); text-decoration-skip-ink: none; text-underline-offset: 3px; }
.lintbar {
  position: absolute; right: 12px; bottom: 10px; z-index: 5; max-width: calc(100% - 80px); padding: 5px 11px; border-radius: 8px; cursor: pointer;
  background: color-mix(in srgb, var(--bad) 12%, var(--surface)); border: 1px solid color-mix(in srgb, var(--bad) 35%, transparent);
  color: var(--bad); font: 12.5px/1.45 ui-monospace, SFMono-Regular, Menlo, monospace; overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
}
.lintbar[hidden] { display: none; }
.lintbar b { font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", sans-serif; margin-right: 8px; }
.hint.keys .sep { margin: 0 8px; }
@media (max-width: 900px) { .hint.keys { display: none; } }

/* ---------- Playground ---------- */
.ws.pg .pane.pg-editor { flex: 1 1 auto; min-width: 0; }
.ws.pg .pane.pg-out { flex: 0 0 40%; border-left: 1px solid var(--line); }
.ws.pg .editor { flex: 1 1 auto; }
.pg-out .scroll { padding: 12px 16px 40px; }
.pg-out .ptabs .navbtn { border: 0; background: transparent; color: var(--muted); font-size: 13px; padding: 5px 8px; border-radius: 7px; cursor: pointer; }
.pg-out .ptabs .navbtn:hover { color: var(--fg); background: var(--hover); }
.pg-run { padding: 10px 0 14px; border-bottom: 1px dashed var(--line); }
.pg-meta { font-size: 12.5px; color: var(--faint); margin-bottom: 4px; }
.pg-meta .ok { color: var(--ok); } .pg-meta .bad { color: var(--bad); }
.pg-img { display: block; max-width: 100%; margin-top: 8px; border-radius: 8px; background: #fff; }
#pg-tpl { height: 32px; max-width: 220px; padding: 0 8px; border: 1px solid var(--line); border-radius: 8px; background: var(--surface); color: var(--fg); font-size: 13px; }
.toast { position: fixed; left: 50%; bottom: 36px; transform: translateX(-50%); z-index: 60; padding: 9px 16px; border-radius: 10px;
  background: var(--fg); color: var(--bg); font-size: 14px; box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2); }
@media (max-width: 900px) {
  .ws.pg .pane.pg-out { flex: none; border-left: 0; border-top: 1px solid var(--line); min-height: 240px; }
  #pg-tpl { max-width: 44vw; }
}