@font-face {
  font-family: "Blue Sky Noto Light";
  src: local("Blue Sky Noto Light"), local("Blue Sky Noto-Light");
  font-display: swap;
}

@font-face {
  font-family: "Blue Sky Noto Regular";
  src: local("Blue Sky Noto Regular"), local("Blue Sky Noto-Regular");
  font-display: swap;
}

:root {
  --font-light: "Blue Sky Noto Light", "PingFang SC Light", -apple-system, BlinkMacSystemFont, "Segoe UI Light", "Microsoft YaHei UI Light", sans-serif;
  --font-regular: "Blue Sky Noto Regular", "PingFang SC", -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei UI", sans-serif;
  --primary: #00B3BE;
  --primary-text: #01A0AC;
  --primary-soft: #E5F9F9;
  --ink: #040B29;
  --muted: #868A9A;
  --line: #CED0D8;
  --line-soft: #E8E9ED;
  --paper: #FFFFFF;
  --soft: #F7F8FA;
  --danger: #E83030;
  --warm: #FFF5ED;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; font-synthesis: none; }
body {
  margin: 0;
  color: var(--ink);
  background: var(--paper);
  font-family: var(--font-light);
  font-size: 14px;
  line-height: 1.6;
}
button, input, textarea { font: inherit; }
h1, h2, h3, h4, h5, h6, strong, b, summary, button, .brand, .brand-mark, .eyebrow, .question-title {
  font-family: var(--font-regular);
  font-weight: normal;
}
button { height: 32px; padding: 0 16px; border: 0; border-radius: 4px; color: #fff; background: var(--primary); cursor: pointer; }
button:hover { background: var(--primary-text); }
button:disabled { cursor: not-allowed; opacity: .45; }
.secondary-button { color: var(--ink); background: #fff; border: 1px solid var(--line); }
.secondary-button:hover { color: var(--ink); background: rgba(156,159,172,.15); border-color: var(--line); }

.sidebar {
  position: fixed;
  inset: 0 auto 0 0;
  z-index: 4;
  display: flex;
  flex-direction: column;
  width: 216px;
  padding: 24px 16px;
  background: #fff;
  border-right: 1px solid var(--line-soft);
}
.brand { display: flex; align-items: center; gap: 10px; font-size: 16px; }
.brand-mark { display: grid; place-items: center; width: 32px; height: 32px; color: #fff; background: var(--primary); }
nav { display: grid; gap: 4px; margin-top: 40px; }
.nav-link { padding: 9px 12px; color: var(--muted); border-left: 2px solid transparent; text-decoration: none; }
.nav-link:hover, .nav-link.active { color: var(--primary-text); background: var(--primary-soft); border-left-color: var(--primary); }
.sidebar-note { margin-top: auto; padding: 16px 12px; color: var(--muted); border-top: 1px solid var(--line-soft); font-size: 12px; }
.sidebar-note span, .sidebar-note strong { display: block; }
.sidebar-note strong { margin-top: 4px; color: var(--ink); font-size: 13px; }

main { max-width: 1600px; margin-left: 216px; padding: 38px 48px 72px; }
.topbar, .section-heading, .split-line, .form-row, .add-task div, .top-actions, .practice-head, .quiz-header, .quiz-progress, .quiz-actions, .plan-day-head, .plan-day-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}
.topbar { min-height: 72px; }
.top-actions { justify-content: flex-end; flex-wrap: wrap; }
.eyebrow { margin: 0 0 4px; color: var(--primary-text); font-size: 12px; }
h1, h2, h3, h4, p { margin-top: 0; }
h1 { max-width: 760px; margin-bottom: 0; font-size: 30px; line-height: 1.3; }
h2 { margin-bottom: 0; font-size: 16px; line-height: 24px; }
h3 { font-size: 16px; }
.section-caption { color: var(--muted); font-size: 13px; }
.sync-status { height: 24px; padding: 3px 8px; color: var(--ink); background: rgba(156,159,172,.2); border-radius: 2px; font-size: 12px; }
.sync-status.online { color: var(--primary-text); background: var(--primary-soft); }
.sync-status.error { color: var(--danger); background: #FFF0F0; }

.hero-grid { display: grid; grid-template-columns: minmax(300px,1.6fr) repeat(3,minmax(160px,1fr)); gap: 16px; margin-top: 28px; }
.countdown-panel, .metric-card { min-height: 164px; padding: 20px; border: 1px solid var(--line-soft); background: #fff; }
.countdown-panel p, .metric-card p { margin-bottom: 6px; color: var(--muted); }
.countdown { display: flex; align-items: baseline; gap: 8px; }
.countdown strong { color: var(--primary-text); font-family: var(--font-regular); font-size: 46px; line-height: 1.1; }
.countdown span { font-size: 16px; }
.muted { font-size: 13px; }
.progress-track { height: 4px; margin: 16px 0 8px; overflow: hidden; background: var(--line-soft); }
.progress-track span { display: block; width: 0; height: 100%; background: var(--primary); transition: width .2s; }
.split-line { color: var(--muted); font-size: 13px; }
.split-line strong { color: var(--ink); }
.metric-card { display: flex; flex-direction: column; }
.metric-card strong { margin: auto 0 3px; font-size: 28px; line-height: 1.1; }
.metric-card span { color: var(--muted); font-size: 13px; }
.alert-card { background: var(--warm); }
.alert-card strong { color: #A45116; }

.section-grid { margin-top: 36px; padding: 28px 0; border-top: 1px solid var(--line-soft); background: #fff; }
.plan-board { margin-top: 24px; }
.plan-summary { display: flex; flex-wrap: wrap; gap: 8px; margin: 16px 0; }
.plan-summary span, .tag { min-height: 24px; padding: 3px 8px; color: var(--ink); background: rgba(156,159,172,.2); border-radius: 2px; font-size: 12px; }
.plan-scroll-shell { width: 100%; overflow: hidden; }
.daily-plan-list {
  display: grid;
  grid-auto-flow: column;
  grid-auto-columns: calc((100% - 72px) / 7);
  gap: 12px;
  overflow-x: auto;
  padding: 2px 0 14px;
  scroll-snap-type: x proximity;
  scrollbar-color: var(--primary) var(--line-soft);
  scrollbar-width: thin;
}
.daily-plan-list:focus { outline: 1px solid var(--primary); outline-offset: 3px; }
.daily-plan-list::-webkit-scrollbar { height: 8px; }
.daily-plan-list::-webkit-scrollbar-track { background: var(--line-soft); }
.daily-plan-list::-webkit-scrollbar-thumb { background: var(--primary); }
.plan-day-card {
  position: relative;
  display: flex;
  flex-direction: column;
  min-width: 0;
  min-height: 270px;
  padding: 16px;
  border: 1px solid var(--line);
  background: #fff;
  scroll-snap-align: start;
  cursor: pointer;
}
.plan-day-card.is-done { background: #F8FCFC; border-color: var(--primary); }
.plan-day-head { align-items: flex-start; }
.plan-weekday { display: block; color: var(--muted); font-size: 12px; }
.plan-day-head strong { font-size: 16px; }
.plan-day-card h3 { margin: 18px 0 8px; font-size: 14px; line-height: 21px; }
.plan-day-card p { flex: 1; margin-bottom: 16px; color: var(--muted); font-size: 13px; }
.plan-day-meta { margin-bottom: 12px; color: var(--muted); font-size: 12px; }
.plan-open { width: 100%; }
.plan-done { display: flex; align-items: center; gap: 7px; margin-top: 12px; color: var(--muted); font-size: 12px; cursor: pointer; }
.plan-done input, .task-item input, .module input { width: 16px; height: 16px; accent-color: var(--primary); }
.extra-plan { margin-top: 18px; border-top: 1px solid var(--line-soft); }
.extra-plan summary { display: flex; justify-content: space-between; padding: 14px 0; cursor: pointer; }
.extra-plan summary span { color: var(--muted); font-family: var(--font-light); font-size: 12px; }
.task-list { border-top: 1px solid var(--line-soft); }
.task-item { display: grid; grid-template-columns: 22px 1fr auto; gap: 12px; align-items: center; padding: 12px 0; border-bottom: 1px solid var(--line-soft); }
.task-item.done .task-name { color: var(--muted); text-decoration: line-through; }
.delete-task, .text-button { height: 24px; padding: 0 8px; color: var(--danger); background: #fff; border: 1px solid var(--danger); border-radius: 2px; font-size: 12px; }
.delete-task:hover, .text-button:hover { color: var(--danger); background: #FFF0F0; }
.add-task { margin-top: 16px; }
.add-task label, .checkin-form label, .auth-form label { color: var(--muted); }
.add-task div { margin-top: 6px; }
.add-task input, .checkin-form input, .checkin-form textarea, .auth-form input {
  width: 100%;
  padding: 9px 10px;
  color: var(--ink);
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 4px;
}
.add-task input:focus, .checkin-form input:focus, .checkin-form textarea:focus, .auth-form input:focus { outline: 1px solid var(--primary); border-color: var(--primary); }
.add-task button { min-width: 72px; }

.checkin-layout { display: grid; grid-template-columns: 1.15fr .85fr; gap: 48px; margin-top: 18px; }
.form-row { align-items: flex-start; }
.form-row label { flex: 1; }
.checkin-form input, .checkin-form textarea { margin-top: 6px; }
.checkin-form textarea { min-height: 88px; resize: vertical; }
.checkin-form button { margin-top: 12px; }
.checkin-history { min-width: 0; }
.log-entry { padding: 11px 0; border-top: 1px solid var(--line-soft); }
.log-entry:first-child { border-top: 0; }
.log-entry p { margin: 3px 0 0; color: var(--muted); }

.subjects-grid { display: grid; grid-template-columns: 1.25fr 1fr; gap: 16px; margin-top: 18px; }
.subject-card { border: 1px solid var(--line); }
.subject-card header { padding: 16px; border-bottom: 1px solid var(--line-soft); }
.subject-card h3 { margin: 0; font-size: 14px; }
.subject-card p { margin: 4px 0 0; color: var(--muted); font-size: 13px; }
.module { display: flex; align-items: flex-start; gap: 10px; padding: 11px 16px; border-bottom: 1px solid var(--line-soft); cursor: pointer; }
.module:last-child { border-bottom: 0; }
.module.is-done span { color: var(--muted); text-decoration: line-through; }

.study-tabs { display: flex; gap: 24px; margin-top: 16px; border-bottom: 1px solid var(--line); }
.study-tab { height: 38px; padding: 8px 4px; color: var(--muted); background: transparent; border-bottom: 2px solid transparent; border-radius: 0; }
.study-tab:hover { color: var(--ink); background: transparent; }
.study-tab.active { color: var(--primary-text); border-bottom-color: var(--primary); background: transparent; }
.study-layout { display: grid; grid-template-columns: 280px 1fr; min-height: 340px; border: 1px solid var(--line); border-top: 0; }
.lesson-list { padding: 8px; border-right: 1px solid var(--line); }
.lesson-button { display: block; width: 100%; height: auto; min-height: 36px; padding: 8px 10px; color: var(--ink); text-align: left; background: #fff; border-radius: 2px; font-size: 13px; }
.lesson-button:hover, .lesson-button.active { color: var(--primary-text); background: var(--primary-soft); }
.lesson-button em { display: inline-grid; place-items: center; width: 18px; height: 18px; margin-right: 7px; color: var(--muted); border: 1px solid var(--line); border-radius: 50%; font-size: 11px; font-style: normal; }
.lesson-button.finished em { color: #fff; background: var(--primary); border-color: var(--primary); }
.lesson-panel { padding: 24px 28px; }
.lesson-panel h3 { margin: 0; }
.lesson-meta { margin: 5px 0 18px; color: var(--muted); font-size: 13px; }
.knowledge-block { padding: 14px 0; border-top: 1px solid var(--line-soft); }
.knowledge-block h4 { margin-bottom: 6px; font-size: 14px; }
.knowledge-block p { margin-bottom: 0; }
.lesson-resources { display: flex; gap: 8px; margin-top: 16px; }
.lesson-resources a, .resource-links a { color: var(--primary-text); text-decoration: none; }
.lesson-resources a { height: 32px; padding: 5px 12px; border: 1px solid var(--primary); border-radius: 4px; }
.lesson-resources a:hover { background: var(--primary-soft); }
.lesson-action { margin-top: 16px; }
.practice-panel { margin-top: 16px; padding: 20px; border: 1px solid var(--line); }
.practice-head { align-items: flex-start; }
.practice-head h3 { margin: 0; font-size: 16px; }
.practice-head span { color: var(--muted); font-size: 13px; }
.question-title { margin: 20px 0 12px; }
.option-list { display: grid; gap: 8px; }
.option { width: 100%; height: auto; min-height: 40px; padding: 9px 12px; color: var(--ink); text-align: left; background: #fff; border: 1px solid var(--line); }
.option:hover { color: var(--primary-text); background: var(--primary-soft); border-color: var(--primary); }
.option.correct { color: var(--primary-text); background: var(--primary-soft); border-color: var(--primary); }
.option.wrong { color: var(--danger); background: #FFF0F0; border-color: var(--danger); }
.answer-explanation { margin: 12px 0 0; padding: 10px 12px; border-left: 3px solid var(--primary); background: var(--soft); }
.next-question { margin-top: 12px; }

.resource-strip { display: grid; grid-template-columns: 1fr 1.2fr; gap: 36px; margin-top: 36px; padding: 28px; color: #fff; background: var(--ink); }
.resource-strip h2 { margin-bottom: 8px; }
.resource-strip p:not(.eyebrow) { margin-bottom: 0; color: #BBBDC7; }
.resource-strip .eyebrow { color: #62D7DE; }
.resource-links { display: grid; grid-template-columns: repeat(2,1fr); gap: 8px; align-content: center; }
.resource-links a { padding: 10px 12px; color: #fff; border: 1px solid #555B70; }
.resource-links a:hover { background: #171F42; border-color: var(--primary); }

.timeline { display: grid; grid-template-columns: repeat(6,1fr); gap: 0; margin: 20px 0 0; padding: 0; list-style: none; }
.timeline li { min-width: 0; padding: 0 16px; border-left: 1px solid var(--line-soft); }
.timeline li:first-child { padding-left: 0; border-left: 0; }
.timeline time { display: inline-block; height: 24px; padding: 3px 8px; color: var(--primary-text); background: var(--primary-soft); border-radius: 2px; font-size: 12px; }
.timeline strong, .timeline span { display: block; }
.timeline strong { margin-top: 10px; }
.timeline span { margin-top: 4px; color: var(--muted); font-size: 12px; }
.timeline .urgent time { color: var(--danger); background: #FFF0F0; }

.auth-backdrop, .quiz-backdrop { position: fixed; z-index: 20; inset: 0; display: grid; place-items: center; padding: 20px; background: rgba(4,11,41,.52); }
.auth-backdrop[hidden], .quiz-backdrop[hidden] { display: none !important; }
.auth-dialog, .quiz-dialog { width: min(440px,100%); max-height: 92vh; overflow: auto; padding: 28px; background: #fff; border: 1px solid var(--line); }
.quiz-dialog { width: min(920px,100%); }
.auth-dialog h2, .quiz-dialog h2 { margin-bottom: 8px; }
.dialog-close { float: right; color: var(--ink); background: #fff; border: 1px solid var(--line); }
.dialog-close:hover { color: var(--ink); background: rgba(156,159,172,.15); }
.auth-copy { color: var(--muted); }
.auth-form { display: grid; gap: 13px; margin-top: 18px; }
.auth-form input { margin-top: 5px; }
.auth-message { min-height: 20px; margin: 0; color: var(--danger); font-size: 13px; }
.auth-message.success { color: var(--primary-text); }
.auth-buttons { display: flex; gap: 8px; }
.daily-study-content { display: grid; grid-template-columns: repeat(2,minmax(0,1fr)); gap: 12px; margin: 18px 0; }
.daily-study-task { grid-column: 1 / -1; margin: 0; padding: 12px; background: var(--primary-soft); }
.daily-study-content section { padding: 16px; border: 1px solid var(--line); }
.daily-study-content section span { color: var(--muted); font-size: 12px; }
.daily-study-content section h3 { margin: 4px 0 10px; font-size: 14px; }
.daily-study-content section p { margin-bottom: 10px; }
.daily-study-content section strong { font-size: 13px; }
.quiz-progress { color: var(--muted); font-size: 13px; }
.quiz-actions { margin-top: 16px; justify-content: flex-end; }

@media (max-width: 1180px) {
  main { padding: 32px 28px 56px; }
  .hero-grid { grid-template-columns: repeat(2,1fr); }
  .countdown-panel { grid-column: span 2; }
  .daily-plan-list { grid-auto-columns: calc((100% - 36px) / 4); }
  .timeline { grid-template-columns: repeat(3,1fr); row-gap: 24px; }
}
@media (max-width: 820px) {
  .sidebar { position: static; width: auto; padding: 16px 20px; border-right: 0; border-bottom: 1px solid var(--line-soft); }
  .sidebar nav { display: flex; margin-top: 16px; overflow-x: auto; }
  .nav-link { flex: 0 0 auto; white-space: nowrap; }
  .sidebar-note { display: none; }
  main { margin-left: 0; }
  .subjects-grid, .checkin-layout, .resource-strip { grid-template-columns: 1fr; }
  .study-layout { grid-template-columns: 220px 1fr; }
}
@media (max-width: 640px) {
  main { padding: 24px 16px 44px; }
  .topbar, .section-heading, .practice-head { align-items: flex-start; flex-direction: column; }
  .top-actions { justify-content: flex-start; }
  h1 { font-size: 26px; }
  .hero-grid { grid-template-columns: 1fr; }
  .countdown-panel { grid-column: auto; }
  .daily-plan-list { grid-auto-columns: minmax(252px,82%); }
  .plan-day-card { min-height: 250px; }
  .form-row, .add-task div { display: block; }
  .form-row label + label { display: block; margin-top: 12px; }
  .add-task button { width: 100%; margin-top: 8px; }
  .study-layout { grid-template-columns: 1fr; }
  .lesson-list { max-height: 230px; overflow-y: auto; border-right: 0; border-bottom: 1px solid var(--line); }
  .lesson-panel { padding: 20px; }
  .resource-links, .daily-study-content { grid-template-columns: 1fr; }
  .timeline { grid-template-columns: 1fr 1fr; }
  .auth-dialog, .quiz-dialog { padding: 20px; }
}