:root {
  color-scheme: light;
  --bg: #f8f8f4;
  --paper: #fefefc;
  --tint: #eef3ed;
  --line: #dce1d9;
  --line-strong: #c8d3ca;
  --text: #192620;
  --muted: #505e55;
  --quiet: #606c63;
  --accent: #225e4d;
  --accent-dark: #164737;
  --error: #922f31;
  --mono: "Cascadia Mono", "SFMono-Regular", Consolas, monospace;
  --sans: "PingFang SC", "Microsoft YaHei", "Noto Sans CJK SC", "Segoe UI", sans-serif;
}

*, *::before, *::after { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--text); font: 15px/1.7 var(--sans); overflow-wrap: anywhere; }
h1, h2, h3, p, figure, form { margin: 0; }
h1, h2, h3, strong { overflow-wrap: anywhere; }
a { color: inherit; text-decoration: none; }
button, input, select, textarea { font: inherit; }
button { cursor: pointer; }
svg { flex-shrink: 0; vertical-align: middle; }
:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }
::selection { background: #d5e6da; color: var(--accent-dark); }

.wrap { width: min(1120px, calc(100% - 80px)); margin-inline: auto; }
.site-header { border-bottom: 1px solid var(--line); background: var(--bg); }
.topbar { min-height: 70px; display: flex; align-items: center; justify-content: space-between; gap: 20px; position: relative; }
.brand { display: inline-flex; align-items: center; gap: 10px; line-height: 1.2; font-size: 15px; font-weight: 700; white-space: nowrap; flex: none; }
.brand-icon { width: 35px; height: 35px; display: grid; place-items: center; border-radius: 7px; background: var(--accent-dark); color: #fff; }
.brand small { display: block; margin-top: 5px; color: var(--quiet); font: 9px/1 var(--mono); letter-spacing: .12em; }
.site-nav { display: flex; justify-content: center; align-items: center; gap: clamp(12px, 2vw, 26px); }
.site-nav a { display: flex; align-items: center; position: relative; min-height: 70px; color: var(--muted); font-size: 13px; font-weight: 550; white-space: nowrap; }
.site-nav a:hover, .site-nav a.active { color: var(--accent-dark); }
.site-nav a.active { font-weight: 700; }
.site-nav a.active::after { content: ""; position: absolute; inset: auto 0 -1px; height: 2px; background: var(--accent); }
.header-actions { min-width: 0; display: flex; align-items: center; gap: 14px; }
.login-link { min-width: 0; display: inline-flex; align-items: center; gap: 6px; white-space: nowrap; font-size: 13px; font-weight: 650; }
.login-link span { max-width: 82px; overflow: hidden; text-overflow: ellipsis; }
.login-link:hover { color: var(--accent); }
.mobile-account { display: none; }
.menu-toggle, .mobile-auth { display: none !important; }
.skip-link { position: fixed; left: 12px; top: 12px; padding: 8px 12px; transform: translateY(-200%); background: var(--accent); color: white; z-index: 5; }
.skip-link:focus { transform: none; }
.main { min-height: calc(100vh - 170px); padding: 40px 0 70px; }
.home-main { padding-top: 0; }
.home-main .flash-stack { margin-top: 20px; }

.button { display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-height: 42px; padding: 8px 16px; border: 1px solid transparent; border-radius: 6px; font-size: 14px; font-weight: 650; line-height: 1.25; text-align: center; transition: background .15s, border-color .15s, color .15s; }
.button.compact { min-height: 35px; padding: 6px 11px; font-size: 13px; }
.button.primary { background: var(--accent); border-color: var(--accent); color: #fff; }
.button.primary:hover { background: var(--accent-dark); border-color: var(--accent-dark); }
.button.secondary { background: var(--paper); border-color: var(--line-strong); color: var(--text); }
.button.secondary:hover { background: var(--tint); border-color: #a7b7aa; color: var(--accent-dark); }
.button.quiet-button { color: var(--accent); padding-inline: 9px; }
.button.quiet-button:hover { background: var(--tint); color: var(--accent-dark); }
.button.danger { background: #fdf8f6; border-color: #e3c9c6; color: var(--error); }
.button.danger:hover { background: #f7e9e6; }

.hero { display: grid; grid-template-columns: minmax(0, 1.06fr) minmax(0, 1fr); align-items: center; gap: clamp(28px, 6vw, 86px); padding: 62px 0 60px; border-bottom: 1px solid var(--line); }
.hero-copy { min-width: 0; }
.hero-kicker { display: flex; align-items: center; gap: 9px; color: var(--accent); font-size: 13px; font-weight: 650; letter-spacing: .08em; }
.hero-kicker::before { content: ""; width: 19px; height: 1px; background: currentColor; }
.hero h1 { margin: 13px 0 16px; font-size: clamp(42px, 5.5vw, 68px); line-height: 1.13; letter-spacing: -.045em; font-weight: 750; }
.hero h1 em { color: var(--accent); font-style: normal; }
.hero p { color: var(--muted); line-height: 1.85; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 9px; margin-top: 23px; }
.hero-art { min-width: 0; padding: 19px 21px 15px; border: 1px solid #d9e2d9; border-radius: 8px; background: #f0f4ef; }
.hero-art figcaption { display: flex; justify-content: space-between; align-items: baseline; gap: 8px; padding-bottom: 10px; border-bottom: 1px solid #dce4dc; color: var(--accent-dark); font-size: 14px; font-weight: 650; }
.figure-note { color: var(--quiet); font-size: 11px; font-weight: 500; white-space: nowrap; }
.hero-art img { width: 100%; height: auto; display: block; margin-block: 5px 2px; }
.figure-steps { display: grid; grid-template-columns: 1fr auto 1fr; gap: 6px; color: var(--quiet); font-size: 12px; }
.figure-steps span:last-child { justify-self: end; }
.figure-steps b { margin-right: 2px; color: var(--accent); font: 600 11px var(--mono); }

.home-split { display: grid; grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr); gap: clamp(22px, 4vw, 48px); margin-top: 27px; }
.home-split.equal { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.home-section { min-width: 0; }
.separated { margin-top: 36px; }
.section-head { display: flex; align-items: baseline; justify-content: space-between; gap: 10px; padding-bottom: 10px; border-bottom: 1px solid var(--line-strong); margin-bottom: 13px; }
.section-head h2 { font-size: 23px; line-height: 1.35; font-weight: 730; letter-spacing: -.025em; }
.more, .back-link { display: inline-flex; align-items: center; gap: 6px; color: var(--muted); font-size: 13px; font-weight: 650; flex-shrink: 0; white-space: nowrap; }
.more:hover, .back-link:hover { color: var(--accent); text-decoration: underline; text-underline-offset: 3px; }
.back-link { margin-bottom: 17px; }
.eyebrow { color: var(--quiet); font-size: 12px; white-space: nowrap; }
.card { min-width: 0; border: 1px solid var(--line); border-radius: 7px; background: var(--paper); }
a.card { transition: border-color .15s, background .15s; }
a.card:hover { border-color: #9eb2a4; }
.notice-list { overflow: hidden; }
.home-section .notice-list { border: 0; border-radius: 0; background: transparent; margin-top: -5px; }
.notice-row { display: grid; grid-template-columns: 53px minmax(0, 1fr) 17px; align-items: center; gap: 13px; min-height: 71px; padding: 11px 14px; }
.home-section .notice-row { padding-inline: 0 3px; }
.notice-row + .notice-row { border-top: 1px solid var(--line); }
.notice-row:hover .notice-title h3, .notice-row:hover .notice-arrow { color: var(--accent); }
.notice-row:hover { background: #f0f3ee; }
.notice-date { align-self: start; margin-top: 3px; color: var(--quiet); font: 500 14px/1.4 var(--mono); }
.notice-title { display: flex; flex-wrap: wrap; align-items: baseline; gap: 2px 9px; margin-bottom: 2px; }
.notice-copy h3 { font-size: 15px; line-height: 1.4; font-weight: 700; }
.notice-copy p, .clamp { display: -webkit-box; -webkit-box-orient: vertical; -webkit-line-clamp: 1; overflow: hidden; }
.notice-copy p { color: var(--muted); font-size: 13px; }
.notice-arrow { color: var(--quiet); justify-self: end; }
.item-tag { max-width: 100%; overflow-wrap: anywhere; color: var(--quiet); font-size: 12px; font-weight: 550; }
.member-name { display: inline-flex; flex-wrap: wrap; align-items: center; gap: 3px 6px; max-width: 100%; vertical-align: middle; white-space: normal; }
.member-name > span { min-width: 0; }
.level-badge { display: inline-block; max-width: 100%; padding: 2px 6px; border: 1px solid var(--line-strong); border-radius: 4px; background: var(--tint); color: var(--accent-dark); font-size: 11px; font-weight: 650; line-height: 1.45; white-space: normal; }
.level-senior { background: var(--accent); border-color: var(--accent); color: white; }
.notice-author { display: block; margin-top: 4px; color: var(--quiet); font-size: 12px; }
.badge { display: inline-flex; align-items: center; gap: 5px; max-width: 100%; padding: 2px 7px; border: 1px solid var(--line); border-radius: 4px; background: #f4f5f1; color: var(--muted); font-size: 11px; font-weight: 650; line-height: 1.5; overflow-wrap: anywhere; }
.badge.lime { background: #e5efe6; border-color: #cfdfd1; color: var(--accent-dark); }
.badge.lime::before { content: ""; width: 5px; height: 5px; border-radius: 50%; background: var(--accent); flex: none; }
.feature-card { min-height: 210px; display: flex; flex-direction: column; padding: 17px 19px 12px; border-color: #d8e2d8; background: var(--tint); }
.feature-copy { margin: auto 0; padding: 14px 0 16px; }
.feature-copy h3 { font-size: 23px; line-height: 1.35; margin-bottom: 6px; letter-spacing: -.02em; }
.feature-copy p { max-width: 32em; color: var(--muted); font-size: 13px; overflow-wrap: anywhere; }
.feature-foot { display: flex; justify-content: space-between; align-items: center; gap: 8px; padding-top: 10px; border-top: 1px solid #d6e1d6; color: var(--accent-dark); font-size: 13px; font-weight: 700; }
.feature-foot:hover { color: var(--accent); }
.line-between { display: flex; justify-content: space-between; align-items: center; gap: 8px 12px; }
.grid { display: grid; min-width: 0; gap: 14px; }
.grid-two { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid-three { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.align-top { align-content: start; align-self: start; }
.story-card { min-height: 145px; display: flex; flex-direction: column; align-items: flex-start; padding: 15px 17px; }
.story-card .line-between, .story-meta { width: 100%; }
.story-card h3 { margin: 7px 0 4px; font-size: 16px; line-height: 1.45; }
.story-card p { margin-bottom: 11px; color: var(--muted); font-size: 13px; overflow-wrap: anywhere; }
.story-meta { display: flex; justify-content: space-between; align-items: center; gap: 8px; margin-top: auto; padding-top: 8px; border-top: 1px solid var(--line); color: var(--quiet); font-size: 12px; }
.story-card:hover .story-meta > svg { color: var(--accent); }
.middle-dot { padding-inline: 5px; color: var(--quiet); }
.inline-icon { display: inline-flex; align-items: center; gap: 4px; }
.empty { min-height: 148px; display: flex; flex-direction: column; justify-content: center; align-items: center; gap: 5px; padding: 20px; border: 1px dashed var(--line-strong); border-radius: 7px; text-align: center; }
.home-split:not(.equal) .empty { min-height: 210px; }
.empty p, .muted { color: var(--muted); font-size: 14px; }
.site-footer { border-top: 1px solid var(--line); }
.footer-inner { display: flex; justify-content: space-between; align-items: center; gap: 16px; min-height: 94px; }
.footer-inner > span { color: var(--quiet); font-size: 12px; }
.footer-inner .brand-icon { width: 32px; height: 32px; }

.page-head { display: flex; justify-content: space-between; align-items: flex-end; gap: 14px; margin-bottom: 22px; padding: 5px 0 20px; border-bottom: 1px solid var(--line-strong); }
.page-head h1, .auth-intro h1 { margin: 5px 0 7px; font-size: clamp(28px, 4vw, 43px); line-height: 1.24; font-weight: 750; letter-spacing: -.035em; }
.page-head p, .auth-intro p { color: var(--muted); overflow-wrap: anywhere; }
.page-head .button { flex: none; }
.page-kicker { display: flex; align-items: center; gap: 7px; color: var(--accent); font-size: 12px; font-weight: 650; letter-spacing: .05em; }
.reading { max-width: 790px; margin-inline: auto; }
.article { padding: clamp(17px, 4vw, 35px); }
.article h1 { margin: 12px 0 8px; font-size: clamp(27px, 4vw, 39px); line-height: 1.28; letter-spacing: -.025em; }
.article-summary { color: var(--muted); font-size: 16px; overflow-wrap: anywhere; }
.meta { display: flex; flex-wrap: wrap; align-items: center; gap: 6px; margin-bottom: 19px; padding: 12px 0 16px; border-bottom: 1px solid var(--line); color: var(--quiet); font-size: 13px; }
.prose { white-space: pre-wrap; overflow-wrap: anywhere; color: #303d35; line-height: 1.9; }
.article > .button, .article > .code-block { margin-top: 21px; }
.code-block { overflow: hidden; border: 1px solid var(--line); border-radius: 6px; background: #f1f4ef; }
.code-head { display: flex; justify-content: space-between; align-items: center; gap: 8px; padding: 6px 10px 6px 13px; border-bottom: 1px solid var(--line); color: var(--accent-dark); font-size: 12px; font-weight: 650; }
.code-head span { display: inline-flex; align-items: center; gap: 6px; }
.code-block pre { overflow: auto; margin: 0; padding: 15px; color: var(--accent-dark); }
code, .code-input { font-family: var(--mono); }
.code-input { color: var(--accent-dark); }
.panel { padding: 18px 20px; }
.panel h2 { margin-bottom: 9px; font-size: 19px; line-height: 1.35; }
.panel .line-between h2 { margin-bottom: 0; }
.panel .line-between + p, .panel .line-between + .form-stack { margin-top: 9px; }
.reading > .panel, .reading > .flash { margin-top: 14px; }
.panel > .button, .panel > p + form { margin-top: 11px; }
.content-split { display: grid; grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr); gap: 17px; align-items: start; }
.manage-bar { margin-bottom: 14px; padding-block: 10px; color: var(--muted); }
.row-actions { display: flex; flex-wrap: wrap; align-items: center; gap: 8px; }
.admin-actions { margin-bottom: 17px; }
.panel-actions { margin-top: 12px; }
.form-stack { display: grid; grid-template-columns: minmax(0, 1fr); gap: 13px; }
.field { display: grid; gap: 5px; min-width: 0; }
.field > span { font-size: 13px; font-weight: 700; }
.field small { color: var(--quiet); font-size: 12px; font-weight: 500; }
.field > span small { margin-left: 7px; }
input:not([type=checkbox]), select, textarea { width: 100%; min-width: 0; padding: 9px 11px; border: 1px solid var(--line-strong); border-radius: 5px; background: var(--paper); color: var(--text); line-height: 1.45; }
input::placeholder, textarea::placeholder { color: #657268; opacity: 1; }
textarea { resize: vertical; }
input[type=file] { max-width: 100%; font-size: 12px; }
input::file-selector-button { margin-right: 8px; padding: 5px 7px; border: 1px solid var(--line-strong); border-radius: 4px; background: var(--tint); color: var(--text); font: inherit; }
input[type=checkbox] { accent-color: var(--accent); }
.checkbox { display: flex; align-items: center; gap: 5px; color: var(--muted); font-size: 13px; }
.hint { color: var(--quiet); font-size: 12px; }
.hint code, .formula code { color: var(--accent-dark); }
.form-divider { border-top: 1px solid var(--line); padding-top: 14px; }
.details { margin: 10px 0; }
.details > div { display: flex; justify-content: space-between; gap: 8px; padding: 6px 0; border-bottom: 1px solid var(--line); font-size: 13px; }
.details dt { color: var(--muted); }
.details dd { margin: 0; text-align: right; }
.formula { display: grid; gap: 5px; margin-top: 10px; padding: 8px 10px; border: 1px solid var(--line); border-radius: 5px; background: var(--tint); overflow-wrap: anywhere; }
.formula span { color: var(--quiet); font-size: 11px; }
.table-scroll { max-width: 100%; overflow: auto; overscroll-behavior-inline: contain; margin-top: 9px; }
table { width: 100%; border-collapse: collapse; font-size: 13px; white-space: nowrap; }
th, td { padding: 8px; border-bottom: 1px solid var(--line); text-align: left; }
th { background: #f4f6f1; color: var(--muted); font-size: 12px; font-weight: 650; }
td code { font-size: 14px; }
.rank { color: var(--quiet); font: 600 13px var(--mono); }
.rank.top { color: var(--accent); }
.contest-jumps, .leaderboard-time-mobile { display: none; }
.inline-empty { margin-top: 11px; padding: 11px 8px; border: 1px dashed var(--line-strong); border-radius: 5px; color: var(--quiet); font-size: 13px; text-align: center; }
.attachment-list, .list-stack, .comment-list { display: grid; gap: 5px; margin-top: 11px; }
.attachment, .list-link { display: flex; justify-content: space-between; align-items: center; gap: 6px 10px; min-width: 0; padding: 8px 10px; border: 1px solid var(--line); border-radius: 5px; background: #f8faf6; }
.attachment:hover, .list-link:hover { border-color: #a7b7aa; color: var(--accent-dark); }
.attachment > span { display: flex; flex-wrap: wrap; align-items: center; gap: 4px 8px; min-width: 0; }
.attachment small, .list-link small { color: var(--quiet); font-size: 12px; overflow-wrap: anywhere; }
.list-link small { display: block; margin-top: 2px; }
.list-link strong { font-size: 13px; }
.subhead { margin-top: 12px; font-size: 13px; }
.plain-list { margin: 3px 0 0; padding: 0; list-style: none; }
.plain-list li { display: flex; justify-content: space-between; align-items: center; padding: 4px 0; border-bottom: 1px solid var(--line); font-size: 12px; }
.plain-list span { color: var(--quiet); }
.info-banner, .flash { display: flex; align-items: center; gap: 8px; padding: 9px 12px; border: 1px solid #d3dfd5; border-radius: 5px; background: var(--tint); color: var(--accent-dark); font-size: 13px; }
.info-banner { margin-bottom: 14px; }
.compact-banner { margin: 0; padding: 6px 8px; }
.flash-stack { display: grid; gap: 5px; margin-bottom: 16px; }
.flash.error { border-color: #e6c8c5; background: #fbefec; color: var(--error); }
.comment, .application { padding: 11px 0; border-top: 1px solid var(--line); }
.comment time { color: var(--quiet); font-size: 12px; }
.comment .prose, .application .prose { font-size: 14px; }
.reply-meta { flex-wrap: wrap; }
.application { margin-top: 8px; }
.application .row-actions { margin-top: 6px; }
.text-link { color: var(--accent); text-decoration: underline; text-underline-offset: 3px; }
.auth-layout { max-width: 790px; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); align-items: center; gap: 22px; margin: 24px auto; }
.auth-intro { min-height: 245px; display: flex; flex-direction: column; justify-content: center; padding: 25px; border: 1px solid #d9e2d9; border-radius: 7px; background: var(--tint); }
.auth-card { padding: 23px; }
.pagination { display: flex; justify-content: center; align-items: center; gap: 12px; margin-top: 16px; color: var(--muted); }
.error-card { max-width: 500px; display: grid; justify-items: start; gap: 8px; margin: 24px auto; padding: 23px; border: 1px solid var(--line); border-radius: 7px; background: var(--paper); }
.error-card h1 { font-size: 50px; line-height: 1.1; }
.error-card p { color: var(--muted); }

.admin-nav { display: flex; flex-wrap: wrap; gap: 3px 16px; margin: -11px 0 22px; border-bottom: 1px solid var(--line); }
.admin-nav a { padding: 7px 4px 9px; border-bottom: 2px solid transparent; color: var(--muted); font-size: 14px; font-weight: 650; white-space: nowrap; }
.admin-nav a.active { border-color: var(--accent); color: var(--accent-dark); }
.admin-nav a:hover { color: var(--accent-dark); }
.admin-metrics { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 12px; margin-bottom: 17px; }
.admin-metric { display: grid; gap: 6px; padding: 13px 15px; color: var(--muted); font-size: 13px; }
.admin-metric div { display: flex; align-items: baseline; justify-content: space-between; gap: 5px; color: var(--accent-dark); }
.admin-metric strong { font: 700 29px/1.2 var(--mono); }
.admin-filters { display: flex; flex-wrap: wrap; align-items: flex-end; gap: 8px 12px; padding: 12px 14px; margin-bottom: 13px; }
.admin-filters > .field { flex: 1 1 125px; max-width: 250px; }
.admin-filters .button { min-height: 39px; }
.admin-table th, .admin-table td { padding: 10px 13px; }
.admin-table tr:last-child td { border-bottom: 0; }
.admin-table td small { display: block; color: var(--quiet); }
.admin-table .note-cell, .admin-table .table-title { max-width: 330px; white-space: normal; overflow-wrap: anywhere; }
.table-title { display: inline-block; color: var(--text); font-weight: 700; }
.table-title:hover { color: var(--accent); text-decoration: underline; text-underline-offset: 3px; }
.account-settings { margin-top: 17px; }
.member-progress { margin-bottom: 17px; }
.progress-current { display: flex; flex-wrap: wrap; align-items: center; gap: 9px 14px; margin-block: 10px 4px; }
.progress-current strong { font-size: 22px; color: var(--accent-dark); }
.progress-current strong span { font-size: 13px; }
.level-breakdown { display: grid; grid-template-columns: repeat(auto-fit, minmax(112px, 1fr)); gap: 8px; margin: 12px 0 0; }
.level-breakdown div { padding: 7px 9px; background: var(--tint); border-radius: 4px; }
.level-breakdown dt { color: var(--quiet); font-size: 12px; }
.level-breakdown dd, .level-rules dd { margin: 0; }
.level-ladder { display: grid; gap: 0; margin: 0; padding: 0; list-style: none; }
.level-ladder li, .level-editor { display: grid; grid-template-columns: 28px minmax(0,1fr) minmax(70px,auto); gap: 10px; align-items: center; padding-block: 8px; border-bottom: 1px solid var(--line); }
.level-ladder li > span:last-child { text-align: right; color: var(--quiet); }
.level-number { font: 650 13px/1 var(--mono); color: var(--accent); }
.level-rules { margin: 0 0 12px; }
.level-rules div { padding: 8px 0; border-bottom: 1px solid var(--line); }
.level-rules dt { font-weight: 700; }
.level-rules dd { color: var(--muted); font-size: 13px; }
.level-editor { grid-template-columns: 28px minmax(0,1fr) minmax(80px,0.4fr); align-items: end; }
.level-editor .level-number { align-self: center; }
.inline-field { display: flex; flex-wrap: wrap; align-items: center; }
.inline-field input { width: auto; max-width: 100%; }
.media-fields { display: grid; gap: 12px; min-width: 0; margin: 0; padding: 12px; border: 1px solid var(--line); border-radius: 6px; }
.media-fields legend { padding-inline: 5px; font-size: 14px; font-weight: 700; }
.media-input-group { display: grid; grid-template-columns: minmax(0, 1fr); gap: 8px; padding-top: 10px; border-top: 1px solid var(--line); }
.material-fields, .review-report { min-width: 0; padding: 10px 12px; border: 1px solid var(--line); border-radius: 6px; background: var(--tint); overflow-wrap: anywhere; }
.material-fields summary { cursor: pointer; font-weight: 650; }
.material-fields > .form-stack { margin-top: 12px; }
.review-report { margin-block: 8px; }
.review-report ul { margin: 8px 0; padding-inline-start: 20px; }
.review-report li + li { margin-top: 7px; }
.review-report li span { display: block; }
.review-report p { margin: 6px 0 0; }
.moderation-entry + .moderation-entry { border-top: 1px solid var(--line); padding-top: 10px; }
.math-block { display: block; max-width: 100%; overflow-x: auto; padding: 9px; margin-block: 9px; border: 1px solid var(--line); border-radius: 6px; }
.formula-source { white-space: pre-wrap; overflow-wrap: anywhere; }
.article-media { display: grid; grid-template-columns: minmax(0, 1fr); gap: 14px; margin-top: 18px; }
.media-item { display: grid; grid-template-columns: minmax(0, 1fr); gap: 7px; padding: 10px; border: 1px solid var(--line); border-radius: 6px; background: var(--tint); }
.media-item img, .media-item video { display: block; max-width: 100%; height: auto; max-height: 550px; margin-inline: auto; object-fit: contain; }
.media-item video, .media-item audio { width: 100%; min-width: 0; }
.media-item figcaption { display: flex; justify-content: space-between; flex-wrap: wrap; gap: 6px; color: var(--muted); font-size: 13px; overflow-wrap: anywhere; }
.learning-series-progress, .learning-lesson-progress, .learning-resource { display: grid; gap: 5px; margin-block: 12px; }
.learning-series-progress progress, .learning-lesson-progress progress, .learning-resource progress { width: 100%; accent-color: var(--accent); }
.learning-lesson-progress { padding: 9px 11px; background: var(--tint); border: 1px solid var(--line); border-radius: 6px; }
.learning-resource form { display: grid; justify-items: start; gap: 5px; }
.learning-resource .button[hidden] { display: none; }
.learning-resource > .badge { justify-self: start; }
.learning-directory { margin-top: 14px; }
.learning-lesson-link > span:first-child { min-width: 0; }
.learning-lesson-link > .row-actions { flex: 0 0 auto; max-width: 42%; justify-content: flex-end; }
[data-scoring-help][hidden] { display: none; }

@media (max-width: 1040px) {
  .wrap { width: calc(100% - 64px); }
  .topbar { gap: 12px; }
  .site-nav { gap: 14px; }
  .header-actions { gap: 9px; }
  .login-link span { max-width: 58px; }
}
@media (max-width: 1080px) {
  .wrap { width: calc(100% - 48px); }
  .topbar { min-height: 62px; gap: 8px; }
  .menu-toggle { order: 2; min-width: 44px; min-height: 44px; display: inline-flex !important; padding-inline: 10px; }
  .header-actions { order: 1; margin-left: auto; }
  .header-actions > .button, .login-link > svg, .login-link .login-name { display: none; }
  .login-link { min-height: 44px; min-width: 44px; justify-content: center; padding-inline: 4px; }
  .login-link .mobile-account { display: inline; max-width: none; }
  .site-nav { display: none; position: absolute; top: 100%; right: 0; left: 0; z-index: 3; padding: 5px 12px; border: 1px solid var(--line-strong); border-radius: 6px; background: var(--paper); box-shadow: 0 7px 18px #14261912; max-height: calc(100vh - 70px); max-height: calc(100dvh - 70px); overflow: auto; overscroll-behavior: contain; }
  .site-nav.is-open { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0 12px; }
  .site-nav a { min-height: 44px; padding-inline: 6px; white-space: normal; }
  .site-nav a.active { background: var(--tint); border-radius: 4px; }
  .site-nav a.active::after { display: none; }
  .mobile-auth { display: flex !important; grid-column: 1 / -1; border-top: 1px solid var(--line); }
  .hero { padding-block: 45px; }
  .notice-row { grid-template-columns: 46px minmax(0, 1fr) 16px; gap: 8px; }
}
@media (max-width: 740px) {
  .hero { grid-template-columns: minmax(0, 1.07fr) minmax(0, 1fr); gap: 18px; }
  .hero-art { padding: 13px 11px 11px; }
  .hero h1 { font-size: clamp(36px, 6.8vw, 48px); }
  .desktop-br { display: none; }
  .figure-steps { font-size: 10px; }
  .figure-steps b { font-size: 9px; }
  .section-head h2 { font-size: 20px; }
  .feature-copy h3 { font-size: 20px; }
}
@media (pointer: coarse), (max-width: 740px) {
  .button { min-height: 44px; }
  input:not([type=checkbox], [type=file]), select, textarea { font-size: 16px; min-height: 44px; }
}
@media (max-width: 620px) {
  .wrap { width: calc(100% - 32px); }
  .main { padding: 25px 0 45px; }
  .home-main { padding-top: 0; }
  .hero { display: block; padding-block: 35px; }
  .hero-art { display: none; }
  .hero p { max-width: 27em; font-size: 14px; }
  .hero-actions { margin-top: 18px; }
  .home-split, .home-split.equal, .content-split, .auth-layout { grid-template-columns: minmax(0, 1fr); }
  .home-split { gap: 25px; margin-top: 23px; }
  .separated { margin-top: 27px; }
  .grid-three { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; }
  .page-head { flex-direction: column; align-items: flex-start; gap: 10px; }
  .feature-card { min-height: 173px; }
  .home-split:not(.equal) .empty { min-height: 148px; }
  .panel { padding: 14px; }
  .auth-layout { max-width: 440px; margin: 0 auto; gap: 12px; }
  .auth-intro { min-height: 0; padding: 13px 16px; }
  .auth-card { padding: 16px; }
  .auth-card .text-link { display: inline-block; padding-block: 8px; }
  .contest-jumps { display: flex; flex-wrap: wrap; gap: 8px; margin: -8px 0 15px; }
  .contest-jumps .button { flex: 1 1 115px; }
  .leaderboard-table { table-layout: fixed; white-space: normal; }
  .leaderboard-table .rank-col { width: 42px; }
  .leaderboard-table .score-col { width: 88px; }
  .leaderboard-table th, .leaderboard-table td { padding-inline: 5px; }
  .leaderboard-time-col { display: none; }
  .leaderboard-time-mobile { display: block; color: var(--quiet); font-size: 11px; }
  .admin-nav { margin-top: -7px; gap: 3px 10px; }
  .admin-nav a { display: flex; align-items: center; min-height: 44px; font-size: 13px; }
  .admin-metrics { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 8px; }
  .admin-filters { align-items: stretch; }
  .admin-table .table-title { min-width: 110px; }
  .manage-bar { flex-wrap: wrap; }
  .footer-inner { flex-wrap: wrap; padding-block: 14px; }
}
@media (max-width: 440px) {
  .grid-three, .grid-two { grid-template-columns: minmax(0, 1fr); }
  .brand { font-size: 14px; }
  .brand-icon { width: 33px; height: 33px; }
  .topbar .brand { gap: 7px; }
  .menu-toggle { padding-inline: 8px; }
  .menu-toggle span { display: none; }
  .level-editor { grid-template-columns: 24px minmax(0, 1fr); }
  .level-editor .field:last-child { grid-column: 2; }
  .footer-inner > span { width: 100%; order: 3; }
}
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { transition: none !important; }
}
.assistant-widget { position: fixed; z-index: 4; right: max(18px, env(safe-area-inset-right)); bottom: max(18px, env(safe-area-inset-bottom)); display: grid; justify-items: end; gap: 10px; width: min(400px, calc(100vw - 36px)); pointer-events: none; }
.assistant-widget > * { pointer-events: auto; }
.assistant-launch { min-height: 46px; border-radius: 24px; box-shadow: 0 5px 18px #19262026; }
.assistant-window { display: grid; grid-template-rows: auto minmax(0, 1fr) auto auto auto; width: 100%; height: min(510px, calc(100vh - 98px)); height: min(510px, calc(100dvh - 98px)); overflow: hidden; box-shadow: 0 12px 38px #1926202e; }
.assistant-window[hidden] { display: none; }
.assistant-header { display: flex; align-items: center; gap: 9px; padding: 11px 12px; border-bottom: 1px solid var(--line); background: var(--tint); }
.assistant-mark { display: grid; place-items: center; width: 34px; height: 34px; border-radius: 7px; background: var(--accent-dark); color: white; }
.assistant-header h2 { font-size: 16px; line-height: 1.3; }
.assistant-header p, .assistant-note { color: var(--quiet); font-size: 12px; }
.assistant-close { margin-left: auto; padding-inline: 10px; font-size: 19px; }
.assistant-log { min-height: 0; padding: 12px; overflow-y: auto; overscroll-behavior: contain; }
.assistant-message { width: fit-content; max-width: 92%; margin-bottom: 9px; padding: 8px 10px; border: 1px solid var(--line); border-radius: 7px; background: var(--tint); font-size: 14px; overflow-wrap: anywhere; }
.assistant-message p { white-space: pre-wrap; }
.assistant-visitor { margin-left: auto; background: var(--paper); border-color: var(--line-strong); }
.assistant-sources { margin: 5px 0 0; padding-left: 17px; font-size: 12px; }
.assistant-contact { display: flex; align-items: center; flex-wrap: wrap; gap: 5px 8px; margin-top: 6px; padding-top: 6px; border-top: 1px solid var(--line-strong); }
.assistant-contact strong { overflow-wrap: anywhere; }
.assistant-prompts { display: flex; flex-wrap: wrap; gap: 5px; padding: 0 12px 8px; }
.assistant-prompts .button { min-height: 30px; padding: 4px 7px; font-size: 12px; }
.assistant-form { display: grid; grid-template-columns: minmax(0, 1fr) auto; gap: 7px; align-items: center; padding: 8px 12px 0; border-top: 1px solid var(--line); }
.assistant-note { padding: 4px 12px 9px; }
.assistant-widget button:disabled { cursor: wait; opacity: .65; }
.rule-fields { border: 0; min-width: 0; margin: 0; padding: 0; }
.assistant-sr-only { position: absolute; width: 1px; height: 1px; clip-path: inset(50%); overflow: hidden; white-space: nowrap; }
@media (max-height: 380px) { .assistant-prompts, .assistant-note { display: none; } .assistant-form { padding-bottom: 8px; } }

.subnav { display: flex; flex-wrap: wrap; gap: 6px 10px; margin: 0 0 19px; }
.subnav a { display: inline-flex; align-items: center; min-height: 42px; padding: 5px 12px; border: 1px solid var(--line); border-radius: 8px; color: var(--text); background: var(--paper); }
.subnav a:hover, .subnav a[aria-current="page"] { border-color: var(--line-strong); background: var(--tint); color: var(--accent-dark); }
.subnav a[aria-current="page"] { font-weight: 700; }
.hub-card { display: grid; align-content: start; gap: 9px; overflow-wrap: anywhere; }
.hub-card:hover, .hub-link:hover { border-color: var(--line-strong); }
.hub-card p, .hub-link small { color: var(--quiet); }
.hub-link { display: flex; align-items: center; justify-content: space-between; flex-wrap: wrap; gap: 8px; margin-bottom: 16px; }
.hub-link strong { display: block; font-size: 18px; }
.hub-link small { display: block; }
.wechat-account { display: flex; align-items: center; gap: 11px; margin: 0; }
.wechat-account img { display: block; width: 92px; height: 92px; background: #fff; }
.wechat-account figcaption { display: grid; gap: 2px; font-size: 12px; }
.wechat-account figcaption span { color: var(--quiet); }
.paper-status { display: grid; gap: 10px; margin-bottom: 14px; overflow-wrap: anywhere; }
.paper-status .line-between, .hub-card .line-between { align-items: flex-start; flex-wrap: wrap; }
.paper-delete { font-size: 13px; color: var(--quiet); }
.paper-delete summary { width: fit-content; cursor: pointer; padding-block: 6px; }
.paper-delete form { margin-top: 8px; }
.paper-list { display: grid; gap: 12px; list-style: none; padding: 0; margin: 0; }
.paper-list h2 { margin: 5px 0; font-size: 18px; }
.paper-list p, .paper-meta { color: var(--quiet); }
.paper-list li, .paper-reader, .paper-prose { overflow-wrap: anywhere; }
.paper-meta { font-size: 13px; }
.paper-reader { max-width: 760px; }
.paper-reader h1 { font-size: clamp(23px, 4vw, 34px); margin: 8px 0; }
.paper-prose { border-top: 1px solid var(--line); margin-top: 24px; padding-top: 18px; }
.paper-prose .hint { margin-block: 12px 16px; }
.paper-body { white-space: pre-wrap; font-size: 17px; line-height: 1.9; }
.paper-status button:disabled { cursor: default; opacity: .55; }
.member-avatar { display: inline-grid; place-items: center; flex: none; vertical-align: middle; border-radius: 50%; object-fit: cover; background: var(--tint); color: var(--accent-dark); }
.avatar-placeholder { width: 24px; height: 24px; }
.avatar-placeholder[data-avatar-size="36"] { width: 36px; height: 36px; }
.avatar-placeholder[data-avatar-size="48"] { width: 48px; height: 48px; }
.avatar-placeholder[data-avatar-size="64"] { width: 64px; height: 64px; }
.avatar-placeholder[data-avatar-size="112"] { width: 112px; height: 112px; }
.member-display, .member-message { overflow-wrap: anywhere; }
.member-message, .presence-label { font-size: 12px; white-space: nowrap; }
.presence-label { display: inline-flex; align-items: center; gap: 4px; font-weight: 500; color: var(--quiet); }
.presence-label::before { content: ""; width: 6px; height: 6px; border-radius: 50%; background: #858e86; }
.presence-label.is-online { color: var(--accent-dark); }
.presence-label.is-online::before { background: #328362; }
.account-welcome .member-avatar { margin-right: 5px; }
.account-shortcuts { margin-bottom: 12px; }
.account-shortcuts .hub-link { margin-bottom: 0; }
.account-connections { margin-bottom: 14px; align-items: start; }
.account-connections section { min-width: 0; }
.account-connections .line-between { flex-wrap: wrap; gap: 3px 10px; }
.account-connections h2 .hint { margin-left: 4px; font-weight: 500; }
.account-connection { gap: 8px; }
.account-connection .connection-name { min-width: 0; }
.account-connection .message-preview { display: block; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.connection-meta { display: grid; justify-items: end; gap: 3px; color: var(--quiet); flex-shrink: 0; font-size: 12px; }
.optional-profile { border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.optional-profile summary { padding-block: 10px; cursor: pointer; color: var(--accent-dark); font-weight: 650; }
.optional-profile .profile-fields { padding: 4px 0 12px; }
.avatar-crop { min-width: 0; margin: 0; display: grid; gap: 9px; }
.avatar-crop legend { padding-inline: 5px; font-weight: 650; }
.avatar-stage { min-height: 112px; display: grid; place-items: center; }
.avatar-stage canvas { width: 112px; height: 112px; border-radius: 50%; outline: 1px solid var(--line); }
.avatar-adjustments { display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: 6px 12px; }
.avatar-adjustments[hidden] { display: none; }
.avatar-adjustments label { display: grid; gap: 2px; }
.avatar-adjustments input[type="range"] { padding: 0; width: 100%; accent-color: var(--accent); border: 0; background: none; }
.avatar-adjustments button { width: max-content; grid-column: 1 / -1; }
.member-hero, .inbox-person { display: flex; align-items: center; gap: 12px; min-width: 0; }
.member-hero h1 { margin: 0 0 3px; }
.profile-public h2:not(:first-child) { margin-top: 15px; }
.profile-public .details { margin-top: 15px; }
.message-inbox .list-link { min-height: 62px; padding: 8px 0; }
.message-inbox .list-link + .list-link { border-top: 1px solid var(--line); }
.chat-relationship { display: grid; gap: 9px; margin-bottom: 12px; }
.chat-warning { color: var(--error); font-size: 14px; font-weight: 600; }
.chat-area { padding: 0; }
.chat-log { max-height: min(58vh, 480px); min-height: 180px; overflow-y: auto; overscroll-behavior: contain; padding: 14px 16px; }
.chat-list { display: grid; gap: 10px; list-style: none; padding: 0; margin: 0; }
.chat-history { margin-bottom: 13px; }
.chat-bubble { width: fit-content; max-width: min(88%, 540px); border-radius: 10px; padding: 8px 11px; background: var(--bg); border: 1px solid var(--line); }
.chat-own .chat-bubble { margin-left: auto; background: var(--tint); }
.chat-bubble p { white-space: pre-wrap; overflow-wrap: anywhere; }
.chat-meta { display: flex; flex-wrap: wrap; gap: 5px 10px; margin-bottom: 3px; color: var(--quiet); font-size: 12px; }
.chat-composer { border-top: 1px solid var(--line); padding: 12px 16px 16px; }
.chat-composer button:disabled { opacity: .52; cursor: default; }
@media (max-width: 620px) {
  .subnav { gap: 5px; margin-bottom: 14px; }
  .subnav a { min-height: 44px; padding-inline: 9px; font-size: 13px; }
  .wechat-account { order: 3; flex-basis: 100%; }
  .chat-log { padding: 11px; }
  .chat-composer { padding: 11px; }
}