@import url('data:text/css,');

:root {
  --ink: #17332d;
  --muted: #64736f;
  --forest: #123c34;
  --forest-2: #20594b;
  --jade: #2c7a67;
  --mint: #dcefe8;
  --paper: #fbf8f0;
  --white: #ffffff;
  --line: #dde4df;
  --coral: #e66c4f;
  --amber: #f4b858;
  --danger: #b33a3a;
  --shadow: 0 20px 50px rgba(18,60,52,.10);
  --radius: 20px;
  --font-display: Cambria, "Noto Serif SC", "Times New Roman", serif;
  font-family: Inter, "Segoe UI", "Noto Sans", Arial, sans-serif;
  color: var(--ink);
  background: var(--paper);
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }
body { margin: 0; min-height: 100vh; background: var(--paper); }
button, input, textarea, select { font: inherit; }
button { cursor: pointer; }
a { color: inherit; }

.login-page {
  min-height: 100vh;
  display: grid;
  grid-template-columns: minmax(360px, 1.05fr) minmax(430px, .95fr);
  background: var(--paper);
}

.login-visual {
  position: relative;
  overflow: hidden;
  padding: clamp(32px, 6vw, 90px);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  color: white;
  background:
    radial-gradient(circle at 78% 18%, rgba(244,184,88,.35), transparent 24%),
    radial-gradient(circle at 18% 88%, rgba(230,108,79,.24), transparent 28%),
    linear-gradient(145deg, #0d3029, #1f5a4b);
}
.login-visual::after {
  content: "学";
  position: absolute;
  right: -3vw;
  bottom: -17vh;
  font: 700 min(52vw, 620px)/1 var(--font-display);
  color: rgba(255,255,255,.045);
  pointer-events: none;
}
.brand { display: flex; gap: 14px; align-items: center; position: relative; z-index: 1; }
.brand-mark { width: 46px; height: 46px; display: grid; place-items: center; border-radius: 15px; background: var(--coral); font: 700 25px var(--font-display); color: white; box-shadow: 0 12px 26px rgba(0,0,0,.16); }
.brand-name { font-weight: 800; font-size: 19px; letter-spacing: .01em; }
.brand-sub { font-size: 12px; opacity: .68; margin-top: 2px; }
.hero-copy { position: relative; z-index: 1; max-width: 650px; }
.eyebrow { font-weight: 800; font-size: 12px; letter-spacing: .16em; text-transform: uppercase; color: var(--amber); }
.hero-copy h1 { font: 700 clamp(43px, 6vw, 84px)/.98 var(--font-display); letter-spacing: -.04em; margin: 18px 0 24px; }
.hero-copy p { max-width: 560px; margin: 0; color: rgba(255,255,255,.76); line-height: 1.75; font-size: 17px; }
.login-proof { display: flex; gap: 28px; position: relative; z-index: 1; color: rgba(255,255,255,.74); font-size: 13px; }
.login-proof strong { display: block; color: white; font: 700 25px var(--font-display); margin-bottom: 4px; }

.login-panel { padding: clamp(28px, 7vw, 100px); display: grid; align-content: center; }
.login-card { width: min(440px, 100%); margin: auto; }
.login-card h2 { font: 700 38px/1.1 var(--font-display); margin: 0 0 12px; color: var(--forest); }
.login-card > p { color: var(--muted); line-height: 1.6; margin-bottom: 32px; }
.demo-box { margin-top: 28px; border: 1px solid var(--line); background: rgba(255,255,255,.72); border-radius: 16px; padding: 16px 18px; font-size: 13px; color: var(--muted); }
.demo-box strong { color: var(--ink); }
.demo-row { display: grid; grid-template-columns: 86px 1fr; gap: 7px; padding: 4px 0; }

.field { display: grid; gap: 8px; margin-bottom: 18px; }
.field label { font-size: 13px; font-weight: 750; color: var(--ink); }
.field small { color: var(--muted); line-height: 1.4; }
input, textarea, select {
  width: 100%; border: 1px solid #ced9d4; background: white; border-radius: 12px;
  padding: 12px 14px; color: var(--ink); outline: none; transition: .18s border, .18s box-shadow;
}
input:focus, textarea:focus, select:focus { border-color: var(--jade); box-shadow: 0 0 0 4px rgba(44,122,103,.11); }
textarea { min-height: 105px; resize: vertical; line-height: 1.55; }
.form-grid { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 0 18px; }
.span-2 { grid-column: span 2; }
.btn { border: 0; border-radius: 12px; padding: 11px 16px; font-weight: 750; display: inline-flex; align-items: center; justify-content: center; gap: 8px; transition: transform .16s, box-shadow .16s, background .16s; }
.btn:hover { transform: translateY(-1px); }
.btn-primary { color: white; background: var(--forest); box-shadow: 0 10px 24px rgba(18,60,52,.17); }
.btn-primary:hover { background: var(--forest-2); }
.btn-coral { color: white; background: var(--coral); }
.btn-soft { color: var(--forest); background: var(--mint); }
.btn-ghost { color: var(--ink); background: transparent; border: 1px solid var(--line); }
.btn-danger { color: var(--danger); background: #fbecec; }
.btn-wide { width: 100%; min-height: 48px; }
.btn-sm { font-size: 12px; padding: 8px 11px; border-radius: 10px; }
.btn:disabled { opacity: .45; cursor: not-allowed; transform: none; box-shadow: none; }

.shell { min-height: 100vh; display: grid; grid-template-columns: 260px 1fr; }
.sidebar { position: sticky; top: 0; height: 100vh; background: var(--forest); color: white; padding: 24px 18px; display: flex; flex-direction: column; z-index: 5; }
.sidebar .brand { padding: 2px 7px 24px; border-bottom: 1px solid rgba(255,255,255,.1); }
.nav { display: grid; gap: 7px; padding: 22px 0; }
.nav button { display: flex; align-items: center; gap: 12px; border: 0; padding: 12px 13px; border-radius: 12px; background: transparent; color: rgba(255,255,255,.67); text-align: left; font-size: 14px; font-weight: 700; }
.nav button:hover, .nav button.active { color: white; background: rgba(255,255,255,.1); }
.nav-icon { width: 26px; text-align: center; font-size: 16px; }
.sidebar-foot { margin-top: auto; display: flex; align-items: center; gap: 10px; padding: 14px 6px 0; border-top: 1px solid rgba(255,255,255,.1); }
.avatar { width: 40px; height: 40px; border-radius: 50%; display: grid; place-items: center; flex: 0 0 auto; background: var(--amber); color: var(--forest); font-weight: 900; }
.user-meta { min-width: 0; flex: 1; }
.user-meta strong { display: block; font-size: 13px; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.user-meta span { font-size: 11px; color: rgba(255,255,255,.58); }
.logout { border: 0; background: none; color: rgba(255,255,255,.55); font-size: 19px; padding: 6px; }
.mobile-logout { display: none !important; }

.main { min-width: 0; }
.topbar { height: 78px; display: flex; align-items: center; justify-content: space-between; padding: 0 clamp(24px,4vw,56px); border-bottom: 1px solid var(--line); background: rgba(251,248,240,.9); backdrop-filter: blur(12px); position: sticky; top: 0; z-index: 4; }
.topbar h1 { font: 700 24px var(--font-display); margin: 0; color: var(--forest); }
.topbar-right { display: flex; align-items: center; gap: 10px; color: var(--muted); font-size: 13px; }
.status-dot { width: 8px; height: 8px; border-radius: 50%; background: #3ca676; box-shadow: 0 0 0 4px rgba(60,166,118,.12); }
.content { padding: 34px clamp(22px,4vw,56px) 70px; max-width: 1500px; margin: 0 auto; }
.class-context { display: flex; align-items: center; justify-content: space-between; gap: 18px; margin-bottom: 22px; padding: 14px 18px; border: 1px solid #cfe0d8; border-radius: 16px; background: rgba(220,239,232,.55); }
.class-context > div { display: grid; gap: 3px; }
.class-context small { color: var(--muted); font-size: 11px; font-weight: 800; text-transform: uppercase; letter-spacing: .07em; }
.class-context strong { color: var(--forest); }
.class-context label { display: flex; align-items: center; gap: 10px; color: var(--muted); font-size: 12px; font-weight: 750; }
.class-context select { min-width: 240px; padding: 9px 12px; }
.page-head { display: flex; align-items: flex-end; justify-content: space-between; gap: 20px; margin-bottom: 28px; }
.page-head h2 { font: 700 clamp(28px,3.5vw,42px)/1.08 var(--font-display); color: var(--forest); margin: 0 0 8px; letter-spacing: -.025em; }
.page-head p { margin: 0; color: var(--muted); line-height: 1.55; }
.actions { display: flex; gap: 10px; flex-wrap: wrap; }

.stats { display: grid; grid-template-columns: repeat(4,minmax(0,1fr)); gap: 16px; margin-bottom: 28px; }
.stat { background: white; border: 1px solid var(--line); border-radius: var(--radius); padding: 20px; box-shadow: 0 6px 20px rgba(18,60,52,.04); }
.stat-label { color: var(--muted); font-size: 12px; font-weight: 700; text-transform: uppercase; letter-spacing: .07em; }
.stat-value { display: flex; align-items: baseline; gap: 7px; margin-top: 12px; font: 700 34px var(--font-display); color: var(--forest); }
.stat-value small { font: 600 12px Inter, sans-serif; color: var(--muted); }

.grid { display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: 18px; }
.grid-2 { grid-template-columns: repeat(2,minmax(0,1fr)); }
.card { background: white; border: 1px solid var(--line); border-radius: var(--radius); padding: 21px; box-shadow: 0 7px 22px rgba(18,60,52,.045); }
.card h3 { margin: 0 0 8px; color: var(--forest); font-size: 17px; }
.card p { color: var(--muted); line-height: 1.55; }
.card-top { display: flex; justify-content: space-between; gap: 12px; align-items: flex-start; }
.tag { display: inline-flex; align-items: center; gap: 5px; border-radius: 99px; padding: 5px 9px; background: var(--mint); color: var(--forest-2); font-size: 11px; font-weight: 800; }
.tag-coral { background: #fbe8e2; color: #a94d35; }
.tag-amber { background: #fff2d7; color: #87611f; }
.muted { color: var(--muted); }
.meta { display: flex; flex-wrap: wrap; gap: 13px; margin-top: 14px; color: var(--muted); font-size: 12px; }
.card-actions { display: flex; gap: 8px; flex-wrap: wrap; margin-top: 18px; padding-top: 16px; border-top: 1px solid #eef1ef; }
.panel { background: white; border: 1px solid var(--line); border-radius: var(--radius); padding: 25px; box-shadow: var(--shadow); }
.panel-title { display: flex; justify-content: space-between; align-items: center; margin-bottom: 20px; }
.panel-title h3 { margin: 0; color: var(--forest); }
.section { margin-top: 32px; }
.section-title { display: flex; justify-content: space-between; align-items: center; margin-bottom: 14px; }
.section-title h3 { margin: 0; font: 700 20px var(--font-display); color: var(--forest); }

.table-wrap { overflow-x: auto; border: 1px solid var(--line); border-radius: 16px; background: white; }
table { width: 100%; border-collapse: collapse; min-width: 660px; }
th { color: var(--muted); font-size: 11px; text-transform: uppercase; letter-spacing: .07em; text-align: left; padding: 13px 16px; background: #f7f8f5; border-bottom: 1px solid var(--line); }
td { padding: 15px 16px; border-bottom: 1px solid #edf1ee; font-size: 13px; }
tr:last-child td { border-bottom: 0; }
.score { font-weight: 850; color: var(--forest); }

.empty { text-align: center; padding: 50px 20px; background: white; border: 1px dashed #cbd8d2; border-radius: var(--radius); color: var(--muted); }
.empty-symbol { font: 700 44px var(--font-display); color: #9ebbb0; margin-bottom: 10px; }
.notice { border-radius: 14px; padding: 14px 16px; background: #fff6e3; border: 1px solid #f4dba6; color: #77561c; line-height: 1.55; font-size: 13px; }
.notice-danger { background: #fcecec; border-color: #efc3c3; color: #8f3030; }

.lesson-hero { padding: clamp(25px,5vw,52px); border-radius: 28px; background: linear-gradient(135deg,var(--forest),var(--forest-2)); color: white; position: relative; overflow: hidden; }
.lesson-hero::after { content: attr(data-zh); position: absolute; right: 3%; top: -20%; font: 700 180px var(--font-display); color: rgba(255,255,255,.055); }
.lesson-hero h2 { font: 700 clamp(38px,6vw,68px) var(--font-display); margin: 8px 0; }
.lesson-hero p { color: rgba(255,255,255,.72); max-width: 700px; line-height: 1.6; }
.vocab-grid { display: grid; grid-template-columns: repeat(3,minmax(0,1fr)); gap: 12px; }
.vocab { padding: 18px; border: 1px solid var(--line); border-radius: 16px; background: white; }
.hanzi { font: 700 31px var(--font-display); color: var(--forest); }
.pinyin { color: var(--coral); font-weight: 700; margin: 3px 0 8px; }
.meaning { color: var(--muted); font-size: 13px; }
.dialogue { display: grid; gap: 10px; }
.line { padding: 14px 16px; border-radius: 14px; background: #f5f8f6; }
.line strong { color: var(--coral); margin-right: 8px; }
.line .zh { font-size: 20px; font-weight: 750; }
.line .py { color: var(--jade); font-size: 13px; margin: 3px 0; }
.line .vi { color: var(--muted); font-size: 13px; }
.lesson-outline { display: grid; gap: 18px; }
.book-section { margin-top: 0; padding: 22px; border: 1px solid var(--line); border-radius: 20px; background: white; }
.book-section-head { display: flex; align-items: flex-start; justify-content: space-between; gap: 12px; margin-bottom: 16px; }
.book-section-head h3 { margin: 0; color: var(--forest); }
.source-chip { display: inline-flex; width: fit-content; padding: 5px 9px; border-radius: 99px; background: #eef3f0; color: var(--muted); font-size: 10px; font-weight: 750; }
.lesson-copy { margin: 0; color: var(--muted); line-height: 1.7; }
.scene-grid { display: grid; gap: 14px; }
.scene-card { border: 1px solid var(--line); border-radius: 16px; padding: 16px; background: #fbfcfa; }
.scene-head { display: flex; gap: 10px; align-items: center; margin-bottom: 12px; }
.scene-head > div { display: flex; flex: 1; justify-content: space-between; align-items: center; gap: 10px; }
.audio-code { display: inline-flex; width: fit-content; padding: 5px 9px; border-radius: 99px; background: #fff2d7; color: #87611f; font-size: 11px; font-weight: 850; white-space: nowrap; }
.mini-vocab { display: grid; gap: 7px; margin-top: 12px; padding-top: 12px; border-top: 1px solid var(--line); }
.mini-vocab > div { display: grid; grid-template-columns: 54px 80px 1fr; gap: 8px; align-items: center; font-size: 12px; color: var(--muted); }
.mini-vocab .zh { color: var(--forest); font-size: 18px; font-weight: 800; }
.mini-vocab .py { color: var(--coral); font-weight: 750; }
.book-grid { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 14px; }
.book-grid h4, .book-section h4 { margin: 0 0 10px; color: var(--forest); }
.sound-grid { display: grid; grid-template-columns: repeat(4,1fr); gap: 7px; }
.sound-grid span, .sound-row span, .word-chip-list span { padding: 8px 10px; border: 1px solid var(--line); border-radius: 10px; background: #f7f9f7; text-align: center; font-weight: 800; color: var(--forest); }
.sound-row { display: flex; flex-wrap: wrap; gap: 7px; margin-bottom: 7px; }
.sound-row span { min-width: 54px; }
.tone-grid { display: grid; grid-template-columns: repeat(4,1fr); gap: 10px; }
.tone-grid article { display: grid; gap: 5px; padding: 14px; border-radius: 14px; background: #f5f8f6; }
.tone-grid article > strong { font: 700 21px var(--font-display); color: var(--forest); }
.tone-grid article > span { color: var(--muted); font-size: 11px; }
.tone-number { color: var(--coral); font-size: 11px; font-weight: 850; text-transform: uppercase; }
.drill-box, .rule-card { margin-top: 14px; padding: 13px 15px; border-radius: 13px; background: #fff6e3; color: #77561c; line-height: 1.65; font-size: 13px; }
.rule-card p { margin: 7px 0 0; }
.compact-table { margin-top: 4px; }
table.book-table { min-width: 0; }
.word-chip-list { display: flex; flex-wrap: wrap; gap: 7px; }
.sandhi-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 9px; }
.sandhi-grid > div { display: flex; justify-content: center; align-items: center; gap: 9px; padding: 12px; border: 1px solid var(--line); border-radius: 12px; }
.sandhi-grid strong { color: var(--coral); }
.phrase-list { display: grid; gap: 8px; }
.phrase-list > div { display: grid; grid-template-columns: 120px 140px 1fr; gap: 10px; align-items: center; padding: 11px 13px; border-radius: 12px; background: #f5f8f6; }
.phrase-list .zh { font-size: 18px; font-weight: 800; color: var(--forest); }
.phrase-list .py { color: var(--coral); font-weight: 750; }
.stroke-grid { display: grid; grid-template-columns: repeat(5,1fr); gap: 9px; }
.stroke-grid article { display: grid; gap: 3px; place-items: center; padding: 12px 8px; border: 1px solid var(--line); border-radius: 13px; }
.stroke-grid article > span, .stroke-grid article > small { color: var(--muted); font-size: 11px; }
.stroke-shape { font: 700 34px var(--font-display) !important; color: var(--forest) !important; }
.subsection-title { margin-top: 22px !important; }
.character-grid { display: grid; grid-template-columns: repeat(3,1fr); gap: 9px; }
.character-grid article { display: flex; gap: 12px; align-items: center; padding: 12px; border: 1px solid var(--line); border-radius: 13px; }
.character { font: 700 34px var(--font-display); color: var(--forest); }
.character-grid article > div { display: grid; gap: 2px; }
.character-grid span, .character-grid small { color: var(--muted); font-size: 11px; }
.workbook-list { display: grid; gap: 8px; }
.workbook-list > div { display: grid; grid-template-columns: 34px 1fr auto; gap: 10px; align-items: center; padding: 10px; border: 1px solid var(--line); border-radius: 12px; }
.workbook-list > div > div { display: grid; gap: 3px; }
.workbook-list small { color: var(--muted); }
.embedded-audio { display: grid; grid-template-columns: minmax(180px,1fr) minmax(240px,1.4fr); align-items: center; gap: 14px; margin: 12px 0 16px; padding: 12px 14px; border: 1px solid #f1d9a9; border-radius: 14px; background: #fff8e9; }
.embedded-audio > div { display: grid; gap: 3px; color: #77561c; }
.embedded-audio span { font-size: 11px; }
.embedded-audio audio { width: 100%; height: 36px; }
.audio-missing { display: flex; justify-content: space-between; gap: 10px; margin: 12px 0; padding: 10px 12px; border-radius: 12px; background: #fcecec; color: #8f3030; font-size: 12px; }
.workbook-exercises { display: grid; gap: 10px; }
.workbook-exercise { border: 1px solid var(--line); border-radius: 14px; background: #fbfcfa; overflow: hidden; }
.workbook-exercise summary { display: grid; grid-template-columns: 34px minmax(0,1fr) auto; gap: 11px; align-items: center; padding: 13px; cursor: pointer; list-style: none; }
.workbook-exercise summary::-webkit-details-marker { display: none; }
.workbook-exercise summary > div { display: grid; gap: 3px; }
.workbook-exercise summary small { color: var(--muted); }
.workbook-exercise[open] summary { border-bottom: 1px solid var(--line); background: white; }
.workbook-exercise-body { padding: 15px; }
.exercise-instruction { margin: 0 0 12px; color: var(--muted); line-height: 1.6; }
.exercise-token-grid { display: grid; grid-template-columns: repeat(4,minmax(0,1fr)); gap: 7px; }
.exercise-token-grid span { display: flex; align-items: center; gap: 7px; padding: 8px 9px; border: 1px solid var(--line); border-radius: 10px; background: white; color: var(--forest); font-weight: 750; }
.exercise-token-grid b, .exercise-prompts b { color: var(--coral); font-size: 10px; min-width: 16px; }
.exercise-prompts { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 8px; }
.exercise-prompts > div { display: flex; gap: 8px; padding: 10px; border-radius: 10px; background: white; border: 1px solid var(--line); }
.exercise-options { display: flex; flex-wrap: wrap; gap: 7px; margin-top: 10px; }
.exercise-options span { padding: 7px 10px; border-radius: 9px; background: #eef3f0; color: var(--forest); font-weight: 750; }
.workbook-answer { display: grid; gap: 4px; margin-top: 14px; padding: 12px 14px; border-radius: 12px; background: #eaf5f0; color: var(--jade); }
.workbook-answer span { font-size: 12px; line-height: 1.6; }
.student-workbook-form { margin-top: 4px; }
.student-answer-grid { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 9px; }
.student-answer-grid label { display: grid; grid-template-columns: minmax(110px,1fr) minmax(120px,.7fr); gap: 10px; align-items: center; padding: 9px 10px; border: 1px solid var(--line); border-radius: 11px; background: white; }
.student-answer-grid label > span { display: flex; align-items: center; gap: 7px; color: var(--forest); font-weight: 750; }
.student-answer-grid label b { color: var(--coral); font-size: 10px; min-width: 16px; }
.student-answer-grid input, .student-answer-grid select { padding: 9px 10px; border-radius: 9px; background: #fbfcfa; }
.student-answer-grid .answer-correct { border-color: #3ca676; background: #edf9f3; box-shadow: 0 0 0 2px rgba(60,166,118,.12); }
.student-answer-grid .answer-wrong { border-color: var(--coral); background: #fff2ef; box-shadow: 0 0 0 2px rgba(220,102,76,.12); }
.workbook-submit { display: flex; align-items: center; justify-content: space-between; gap: 14px; margin-top: 14px; padding-top: 13px; border-top: 1px solid var(--line); }
.workbook-live-result { display: grid; gap: 3px; color: var(--muted); font-size: 12px; }
.workbook-live-result strong { font-size: 15px; }
.workbook-live-result.all-correct { color: #23734f; }
.workbook-live-result.needs-review { color: #a44531; }
.practice-done { background: #dff3e9 !important; color: #23734f !important; }

.question { padding: 20px 0; border-bottom: 1px solid var(--line); }
.question:last-child { border: 0; }
.question-head { display: flex; gap: 12px; }
.number { width: 30px; height: 30px; flex: 0 0 auto; display: grid; place-items: center; background: var(--mint); color: var(--forest); border-radius: 10px; font-weight: 850; }
.question h4 { margin: 2px 0 6px; }
.options { display: grid; gap: 9px; margin: 14px 0 0 42px; }
.option { display: flex; align-items: center; gap: 10px; padding: 11px 13px; border: 1px solid var(--line); border-radius: 12px; background: white; }
.option input { width: auto; }
.token-row { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 12px; }
.token { border: 1px solid var(--line); background: white; color: var(--forest); border-radius: 10px; padding: 8px 12px; font-weight: 800; }
.token.chosen { background: var(--forest); color: white; }
.order-preview { min-height: 44px; margin: 12px 0; padding: 10px 12px; border-radius: 10px; background: #f5f8f6; color: var(--jade); }
.result-correct { border-left: 4px solid #3ca676; padding-left: 15px; }
.result-wrong { border-left: 4px solid var(--coral); padding-left: 15px; }
.explain { background: #f5f8f6; padding: 11px 13px; border-radius: 10px; color: var(--muted); font-size: 13px; line-height: 1.5; margin-top: 9px; }
.progress-track { height: 9px; border-radius: 99px; background: #e7ece9; overflow: hidden; }
.progress-fill { height: 100%; background: linear-gradient(90deg,var(--jade),#58a78d); border-radius: inherit; }
.roster { display: grid; gap: 8px; margin-top: 18px; padding-top: 16px; border-top: 1px solid var(--line); }
.roster > strong { color: var(--forest); font-size: 13px; }
.roster-row { display: flex; align-items: center; justify-content: space-between; gap: 10px; padding: 8px 0; border-bottom: 1px solid #edf1ee; font-size: 13px; }
.roster-row:last-child { border-bottom: 0; }
.roster-row small { color: var(--muted); }

.workflow { display: grid; grid-template-columns: repeat(4,1fr); gap: 12px; align-items: stretch; }
.workflow-step { position: relative; padding: 18px; border: 1px solid var(--line); border-radius: 16px; background: white; }
.workflow-step:not(:last-child)::after { content: "→"; position: absolute; right: -15px; top: 42%; color: var(--coral); font-weight: 900; z-index: 1; }
.workflow-step b { display: block; margin-bottom: 7px; color: var(--forest); }
.workflow-step span { color: var(--muted); font-size: 12px; line-height: 1.5; }

.hsk-rail { display: flex; align-items: center; gap: 18px; margin: 0 0 24px; padding: 14px; border: 1px solid var(--line); border-radius: 18px; background: rgba(255,255,255,.72); }
.hsk-rail-copy { min-width: 110px; padding: 2px 8px; display: grid; gap: 3px; }
.hsk-rail-copy small { color: var(--muted); font-size: 11px; }
.hsk-rail-copy strong { color: var(--forest); }
.hsk-levels { min-width: 0; display: flex; flex: 1; gap: 8px; overflow-x: auto; padding-bottom: 2px; scrollbar-width: thin; }
.hsk-level { min-width: 78px; display: flex; align-items: center; justify-content: space-between; gap: 9px; padding: 10px 11px; border: 1px solid var(--line); border-radius: 12px; background: white; color: var(--muted); font-size: 12px; font-weight: 800; white-space: nowrap; }
.hsk-level b { min-width: 21px; height: 21px; padding: 0 5px; display: grid; place-items: center; border-radius: 8px; background: #edf3f0; color: var(--jade); font-size: 10px; }
.hsk-level:hover { border-color: #9fc7ba; color: var(--forest); }
.hsk-level.active { border-color: var(--forest); background: var(--forest); color: white; box-shadow: 0 8px 18px rgba(18,60,52,.16); }
.hsk-level.active b { background: rgba(255,255,255,.16); color: white; }

.exam-shell { min-height: 310px; display: grid; grid-template-columns: 120px minmax(0,620px); align-items: center; justify-content: center; gap: 32px; padding: 46px; border: 1px dashed #b9ccc5; border-radius: 24px; background: linear-gradient(135deg,rgba(255,255,255,.9),rgba(220,239,232,.38)); text-align: left; }
.exam-empty-mark { width: 112px; height: 112px; display: grid; place-items: center; border-radius: 32px; background: var(--forest); color: white; font: 700 54px var(--font-display); box-shadow: 0 18px 35px rgba(18,60,52,.18); }
.exam-shell h3 { margin: 14px 0 8px; font: 700 27px var(--font-display); color: var(--forest); }
.exam-shell p { margin: 0; color: var(--muted); line-height: 1.7; }
.exam-plan { display: flex; flex-wrap: wrap; gap: 9px; margin-top: 20px; }
.exam-plan span { display: flex; align-items: center; gap: 7px; padding: 8px 11px; border-radius: 10px; background: white; border: 1px solid var(--line); color: var(--forest); font-size: 12px; font-weight: 750; }
.exam-plan b { width: 20px; height: 20px; display: grid; place-items: center; border-radius: 7px; background: var(--mint); color: var(--jade); font-size: 10px; }

.modal-backdrop { position: fixed; inset: 0; z-index: 20; background: rgba(9,34,29,.62); display: grid; place-items: center; padding: 20px; backdrop-filter: blur(4px); }
.modal { width: min(780px,100%); max-height: 92vh; overflow: auto; background: var(--paper); border-radius: 24px; box-shadow: 0 30px 90px rgba(0,0,0,.28); }
.modal:has(.lesson-outline) { width: min(1050px,100%); }
.modal-head { display: flex; justify-content: space-between; align-items: center; padding: 22px 24px; border-bottom: 1px solid var(--line); position: sticky; top: 0; background: var(--paper); z-index: 1; }
.modal-head h3 { margin: 0; color: var(--forest); }
.modal-body { padding: 24px; }
.close { border: 0; background: #e8eeeb; width: 34px; height: 34px; border-radius: 50%; color: var(--forest); font-size: 18px; }
.check-list { max-height: 250px; overflow: auto; display: grid; gap: 8px; padding: 4px; }
.check-item { display: flex; gap: 10px; padding: 10px; border: 1px solid var(--line); border-radius: 11px; background: white; }
.check-item input { width: auto; }

.toast { position: fixed; right: 24px; bottom: 24px; z-index: 50; max-width: 380px; transform: translateY(30px); opacity: 0; pointer-events: none; transition: .25s; background: var(--forest); color: white; padding: 14px 18px; border-radius: 13px; box-shadow: var(--shadow); font-size: 13px; }
.toast.show { transform: translateY(0); opacity: 1; }
.toast.error { background: var(--danger); }
.loading { min-height: 45vh; display: grid; place-items: center; color: var(--muted); }
.spinner { width: 36px; height: 36px; border: 3px solid var(--mint); border-top-color: var(--jade); border-radius: 50%; animation: spin .75s linear infinite; }
@keyframes spin { to { transform: rotate(360deg); } }

@media (max-width: 1050px) {
  .login-page { grid-template-columns: 1fr; }
  .login-visual { min-height: 42vh; padding: 35px; }
  .login-proof { display: none; }
  .login-panel { padding: 45px 25px; }
  .stats { grid-template-columns: repeat(2,1fr); }
  .grid { grid-template-columns: repeat(2,1fr); }
  .workflow { grid-template-columns: repeat(2,1fr); }
  .workflow-step::after { display: none; }
}
@media (max-width: 760px) {
  .shell { grid-template-columns: 1fr; }
  .sidebar { position: fixed; bottom: 0; top: auto; height: 72px; width: 100%; max-width: 100vw; padding: 8px 10px; flex-direction: row; overflow: hidden; z-index: 10; }
  .sidebar .brand, .sidebar-foot { display: none; }
  .nav { width: 100%; min-width: 0; display: grid; grid-auto-flow: column; grid-auto-columns: minmax(48px,1fr); overflow-x: auto; scrollbar-width: none; padding: 0; gap: 4px; }
  .nav::-webkit-scrollbar { display: none; }
  .nav button { min-width: 0; padding: 7px 2px; flex-direction: column; gap: 3px; justify-content: center; font-size: 9px; line-height: 1.05; white-space: normal; }
  .nav .mobile-logout { display: flex !important; }
  .nav-icon { width: auto; font-size: 18px; }
  .topbar { height: 64px; padding: 0 18px; }
  .topbar h1 { font-size: 19px; }
  .topbar-right { display: none; }
  .content { padding: 24px 16px 100px; }
  .class-context { align-items: stretch; flex-direction: column; }
  .class-context label { align-items: stretch; flex-direction: column; gap: 6px; }
  .class-context select { min-width: 0; }
  .page-head { align-items: flex-start; flex-direction: column; }
  .stats, .grid, .grid-2, .vocab-grid, .form-grid, .workflow { grid-template-columns: 1fr; }
  .span-2 { grid-column: span 1; }
  .hero-copy h1 { font-size: 43px; }
  .login-visual { min-height: 360px; }
  .options { margin-left: 0; }
  .book-section { padding: 16px; }
  .book-section-head, .scene-head > div { flex-direction: column; align-items: flex-start; }
  .book-grid, .tone-grid, .sandhi-grid { grid-template-columns: 1fr; }
  .phrase-list > div { grid-template-columns: 1fr; }
  .stroke-grid { grid-template-columns: repeat(2,1fr); }
  .character-grid { grid-template-columns: repeat(2,1fr); }
  .workbook-list > div { grid-template-columns: 34px 1fr; }
  .workbook-list .audio-code, .workbook-list .source-chip { grid-column: 2; }
  .embedded-audio { grid-template-columns: 1fr; }
  .workbook-exercise summary { grid-template-columns: 34px 1fr; }
  .workbook-exercise summary .audio-code, .workbook-exercise summary .source-chip { grid-column: 2; }
  .exercise-token-grid, .exercise-prompts { grid-template-columns: repeat(2,minmax(0,1fr)); }
  .student-answer-grid { grid-template-columns: 1fr; }
  .student-answer-grid label { grid-template-columns: 1fr; }
  .workbook-submit { align-items: stretch; flex-direction: column; }
  .mini-vocab > div { grid-template-columns: 45px 70px 1fr; }
  .hsk-rail { align-items: stretch; flex-direction: column; gap: 10px; padding: 12px; }
  .hsk-rail-copy { padding: 0 2px; }
  .hsk-levels { width: 100%; }
  .hsk-level { min-width: 82px; }
  .exam-shell { grid-template-columns: 1fr; padding: 30px 22px; text-align: center; }
  .exam-empty-mark { width: 88px; height: 88px; margin: auto; font-size: 42px; border-radius: 26px; }
  .exam-plan { justify-content: center; }
}