:root {
  --ink: #16231c;
  --muted: #667169;
  --paper: #f5f2e9;
  --card: #fffdf7;
  --line: #dedbd1;
  --green: #1f5b45;
  --green-dark: #153d30;
  --green-soft: #e6eee8;
  --gold: #c6923f;
  --rose: #a74d43;
  --shadow: 0 20px 50px rgba(30, 52, 40, 0.08);
  font-family: Inter, Pretendard, "Noto Sans KR", system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  color: var(--ink);
  background: var(--paper);
  font-synthesis: none;
}

* { box-sizing: border-box; }
[hidden] { display: none !important; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  min-width: 320px;
  background:
    radial-gradient(circle at 8% 0%, rgba(198, 146, 63, 0.08), transparent 28rem),
    var(--paper);
}

button, input, select, textarea { font: inherit; }
button { cursor: pointer; }

.site-header {
  position: sticky;
  z-index: 20;
  top: 0;
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 76px;
  padding: 12px clamp(20px, 5vw, 72px);
  border-bottom: 1px solid rgba(22, 35, 28, 0.09);
  background: rgba(245, 242, 233, 0.9);
  backdrop-filter: blur(14px);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: inherit;
  text-decoration: none;
}

.brand-mark, .coach-avatar {
  display: grid;
  flex: 0 0 auto;
  width: 42px;
  height: 42px;
  place-items: center;
  border-radius: 12px;
  color: #fff;
  background: var(--green);
  font-family: Georgia, serif;
  font-size: 21px;
  font-weight: 700;
  box-shadow: inset 0 0 0 1px rgba(255, 255, 255, 0.18);
}

.brand strong { display: block; font-family: Georgia, "Times New Roman", serif; font-size: 19px; letter-spacing: 0.01em; }
.brand small { display: block; margin-top: 2px; color: var(--muted); font-size: 11px; }

.system-status { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: 8px; }
.header-tools { display: flex; align-items: center; justify-content: flex-end; gap: 14px; }
.account-controls { display: flex; align-items: center; gap: 9px; padding-left: 14px; border-left: 1px solid var(--line); }
.account-controls span { max-width: 170px; overflow: hidden; color: var(--muted); font-size: 11px; font-weight: 700; text-overflow: ellipsis; white-space: nowrap; }
.status-pill {
  padding: 7px 10px;
  border: 1px solid var(--line);
  border-radius: 999px;
  color: var(--muted);
  background: rgba(255,255,255,0.55);
  font-size: 11px;
  font-weight: 700;
}
.status-pill.ready { border-color: #b8cdbf; color: var(--green); background: var(--green-soft); }
.status-pill.demo { border-color: #dfcba7; color: #795c28; background: #f7edda; }

main { width: min(1180px, calc(100% - 40px)); margin: 0 auto; }

.app-navigation {
  display: inline-flex;
  gap: 4px;
  margin-top: 18px;
  padding: 5px;
  border: 1px solid rgba(22, 35, 28, 0.1);
  border-radius: 13px;
  background: rgba(255, 253, 247, 0.72);
}
.app-nav-button { min-width: 94px; min-height: 38px; padding: 0 16px; border: 0; border-radius: 9px; color: var(--muted); background: transparent; font-size: 12px; font-weight: 800; }
.app-nav-button.active { color: #fff; background: var(--green); box-shadow: 0 7px 18px rgba(31, 91, 69, 0.18); }

.auth-gate { width: min(560px, 100%); margin: clamp(70px, 12vw, 150px) auto; padding: clamp(28px, 5vw, 48px); text-align: center; }
.auth-gate h1 { margin: 0; font-family: Georgia, "Noto Serif KR", serif; font-size: clamp(32px, 5vw, 48px); font-weight: 500; }
.auth-gate > p:not(.step-label) { margin: 18px auto 26px; color: var(--muted); line-height: 1.75; }
.auth-gate .primary-button { margin: 0 auto; }

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.35fr) minmax(280px, 0.65fr);
  gap: clamp(30px, 6vw, 90px);
  align-items: end;
  padding: clamp(56px, 9vw, 116px) 0 48px;
}

.eyebrow, .step-label, .message-label {
  margin: 0 0 12px;
  color: var(--green);
  font-size: 11px;
  font-weight: 800;
  letter-spacing: 0.16em;
}

.hero h1 {
  max-width: 760px;
  margin: 0;
  font-family: Georgia, "Noto Serif KR", serif;
  font-size: clamp(42px, 6.7vw, 82px);
  font-weight: 500;
  letter-spacing: -0.055em;
  line-height: 1.03;
}

.hero-copy { margin: 0 0 8px; color: var(--muted); font-size: 16px; line-height: 1.85; }

.profile-strip { display: grid; grid-template-columns: minmax(220px, 0.65fr) minmax(0, 1.35fr); gap: 32px; align-items: center; margin-bottom: 22px; padding: 24px 30px; }
.profile-strip h2 { margin: 0; font-family: Georgia, "Noto Serif KR", serif; font-size: 25px; font-weight: 500; }
.profile-strip > div > p:last-child { margin: 8px 0 0; color: var(--muted); font-size: 12px; line-height: 1.6; }
.profile-form { display: grid; grid-template-columns: 1fr minmax(190px, 1.3fr) minmax(110px, 0.5fr) auto; gap: 10px; align-items: end; }
.profile-form .field-label { margin: 0 0 7px; }
.profile-form .secondary-button { min-height: 48px; }
.profile-message { grid-column: 1 / -1; min-height: 16px; margin: 0; color: var(--green); font-size: 11px; }

.setup-grid { display: grid; grid-template-columns: minmax(0, 1.55fr) minmax(280px, 0.7fr); gap: 22px; }

.card {
  border: 1px solid rgba(22, 35, 28, 0.11);
  border-radius: 22px;
  background: var(--card);
  box-shadow: var(--shadow);
}

.input-card { padding: clamp(24px, 4vw, 42px); }
.principle-card { padding: 34px; background: var(--green-dark); color: #fff; }
.principle-card .step-label { color: #a9c2b6; }
.principle-card h2 { margin: 0 0 28px; font-family: Georgia, serif; font-size: 32px; font-weight: 500; }

.section-heading, .analysis-header, .scene-title-row, .progress-row, .form-actions, .scene-navigation {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.section-heading h2, .analysis-header h2 { margin: 0; font-family: Georgia, "Noto Serif KR", serif; font-size: clamp(28px, 3vw, 38px); font-weight: 500; }

.field-label { display: block; margin: 24px 0 9px; color: #465249; font-size: 12px; font-weight: 800; }

textarea, input, select {
  width: 100%;
  border: 1px solid #d4d2c9;
  border-radius: 12px;
  outline: none;
  color: var(--ink);
  background: #fbfaf5;
  transition: border-color 150ms, box-shadow 150ms, background 150ms;
}

textarea { resize: vertical; padding: 16px; line-height: 1.65; }
input, select { min-height: 48px; padding: 0 13px; }
textarea:focus, input:focus, select:focus { border-color: var(--green); background: #fff; box-shadow: 0 0 0 3px rgba(31, 91, 69, 0.11); }

.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 16px; }
.form-row .field-label { margin-top: 18px; }

.toggle-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
  margin: 20px 0 26px;
  padding: 15px 17px;
  border: 1px solid var(--line);
  border-radius: 13px;
  background: #faf8f1;
}
.toggle-row strong, .toggle-row small { display: block; }
.toggle-row strong { font-size: 13px; }
.toggle-row small { margin-top: 5px; color: var(--muted); font-size: 11px; }
.toggle-row input { width: 20px; min-height: 20px; accent-color: var(--green); }

.primary-button, .secondary-button, .next-button, .icon-button, .text-button {
  border: 0;
  font-weight: 800;
  transition: transform 150ms, background 150ms, opacity 150ms;
}
.primary-button:hover, .secondary-button:hover, .next-button:hover, .icon-button:hover { transform: translateY(-1px); }
.primary-button {
  display: inline-flex;
  align-items: center;
  justify-content: space-between;
  min-width: 210px;
  min-height: 52px;
  padding: 0 19px;
  border-radius: 12px;
  color: #fff;
  background: var(--green);
}
.primary-button:hover { background: var(--green-dark); }
.primary-button:disabled { cursor: wait; opacity: 0.65; transform: none; }
.primary-button.compact { min-width: 0; min-height: 44px; justify-content: center; }
.secondary-button { min-height: 42px; padding: 0 15px; border: 1px solid var(--line); border-radius: 10px; color: var(--ink); background: transparent; }
.text-button { padding: 5px 0; color: var(--green); background: transparent; font-size: 12px; }
.form-note { margin: 0; color: var(--muted); font-size: 11px; line-height: 1.5; }

.error-message, .warning-item { margin-top: 16px; padding: 13px 15px; border-radius: 10px; font-size: 12px; line-height: 1.55; }
.error-message { color: #842f2b; background: #f8e3df; }

.target-list { margin: 0; padding: 0; list-style: none; }
.target-list li { display: grid; grid-template-columns: 34px 1fr; gap: 12px; align-items: start; padding: 17px 0; border-top: 1px solid rgba(255,255,255,0.12); }
.target-list li > span { color: #a9c2b6; font-family: Georgia, serif; font-size: 13px; }
.target-list p { margin: 0; }
.target-list strong, .target-list small { display: block; }
.target-list strong { font-size: 14px; }
.target-list small { margin-top: 5px; color: #bdc9c2; font-size: 11px; line-height: 1.5; }
blockquote { margin: 26px 0 0; padding: 18px 0 0; border-top: 1px solid rgba(255,255,255,0.12); color: #dce6e0; font-family: Georgia, "Noto Serif KR", serif; font-size: 18px; line-height: 1.6; }

.analysis-section { padding: 86px 0 40px; scroll-margin-top: 76px; }
.game-meta { margin: 10px 0 0; color: var(--muted); font-size: 13px; }
.warning-list:not(:empty) { display: grid; gap: 8px; margin: 18px 0; }
.warning-item { margin: 0; border: 1px solid #e2cfae; color: #715729; background: #f8efde; }

.review-layout { display: grid; grid-template-columns: minmax(0, 1.05fr) minmax(340px, 0.86fr); gap: 22px; margin-top: 26px; }
.board-panel, .coach-panel { min-width: 0; padding: clamp(20px, 3vw, 34px); }
.scene-title-row { align-items: flex-start; }
.scene-title-row h3, .metrics-card h3 { margin: 0; font-family: Georgia, "Noto Serif KR", serif; font-size: 25px; font-weight: 500; }
.classification-badge { flex: 0 0 auto; padding: 7px 10px; border-radius: 999px; color: var(--green); background: var(--green-soft); font-size: 11px; font-weight: 800; }
.classification-badge.bad { color: #8d332e; background: #f8e1dd; }
.classification-badge.warn { color: #75571d; background: #f6ebd2; }

.board-wrap { display: grid; width: min(100%, 560px); margin: 25px auto; place-items: center; }
.chessboard { display: grid; width: 100%; aspect-ratio: 1; grid-template-columns: repeat(8, 1fr); overflow: hidden; border: 8px solid #263b31; border-radius: 8px; box-shadow: 0 16px 30px rgba(22,35,28,0.18); }
.square { position: relative; display: grid; place-items: center; font-family: "Segoe UI Symbol", "Arial Unicode MS", sans-serif; font-size: clamp(27px, 5vw, 52px); line-height: 1; user-select: none; }
.square.light { background: #e7ddc5; }
.square.dark { background: #77927d; }
.square .piece { filter: drop-shadow(0 2px 1px rgba(0,0,0,0.18)); }
.square .coordinate { position: absolute; right: 4px; bottom: 2px; font: 700 9px/1 system-ui, sans-serif; opacity: 0.55; }

.engine-strip { display: grid; grid-template-columns: repeat(3, 1fr); overflow: hidden; border: 1px solid var(--line); border-radius: 12px; }
.engine-strip div { padding: 13px 15px; border-right: 1px solid var(--line); }
.engine-strip div:last-child { border-right: 0; }
.engine-strip span, .engine-strip strong { display: block; }
.engine-strip span { margin-bottom: 5px; color: var(--muted); font-size: 10px; }
.engine-strip strong { font-size: 14px; }
.pv-line { min-height: 18px; margin: 12px 2px 0; color: var(--muted); font-family: ui-monospace, SFMono-Regular, Consolas, monospace; font-size: 11px; }
.move-navigation { display: grid; grid-template-columns: auto auto minmax(100px, 1fr) auto auto; gap: 8px; align-items: center; margin: -8px 0 18px; }
.move-navigation strong { color: var(--muted); font-size: 11px; text-align: center; }
.move-button { min-height: 38px; padding: 0 11px; border: 1px solid var(--line); border-radius: 9px; color: var(--ink); background: #fff; font-size: 11px; font-weight: 800; }
.move-button.primary { border-color: var(--green); color: #fff; background: var(--green); }
.move-button:disabled { cursor: default; opacity: 0.35; }

.coach-panel { display: flex; flex-direction: column; }
.progress-row { color: var(--muted); font-size: 11px; font-weight: 800; }
.progress-track { flex: 1; height: 5px; overflow: hidden; border-radius: 999px; background: #e7e7df; }
.progress-track span { display: block; width: 33%; height: 100%; border-radius: inherit; background: var(--green); transition: width 250ms; }

.coach-message { display: flex; gap: 14px; margin-top: 30px; padding-bottom: 24px; border-bottom: 1px solid var(--line); }
.coach-avatar { width: 38px; height: 38px; border-radius: 50%; font-size: 17px; }
.coach-message p:last-child { margin: 0; font-family: Georgia, "Noto Serif KR", serif; font-size: clamp(20px, 2.2vw, 27px); line-height: 1.5; }
.question-message .message-label { margin-bottom: 8px; }

.reflection-box { margin-top: 20px; }
.reflection-box label { display: block; margin-bottom: 8px; font-size: 11px; font-weight: 800; }
.reflection-box textarea { min-height: 88px; }
.coach-actions { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-top: 14px; }

.reveal-card { margin-top: 14px; padding: 17px; border: 1px solid var(--line); border-radius: 12px; background: #faf8f1; }
.reveal-card > p:last-child { margin: 0; color: #3f4b43; font-size: 13px; line-height: 1.7; }
.explanation-card { border-color: #c9d8ce; background: var(--green-soft); }
.memory-rule { margin-top: 16px; padding-top: 15px; border-top: 1px solid rgba(31,91,69,0.18); }
.memory-rule span, .memory-rule strong { display: block; }
.memory-rule span { margin-bottom: 6px; color: var(--green); font-size: 10px; font-weight: 800; letter-spacing: 0.08em; }
.memory-rule strong { font-family: Georgia, "Noto Serif KR", serif; font-size: 16px; line-height: 1.5; }

.scene-navigation { margin-top: auto; padding-top: 24px; }
.icon-button { width: 42px; height: 42px; border: 1px solid var(--line); border-radius: 50%; color: var(--ink); background: transparent; }
.icon-button:disabled { cursor: default; opacity: 0.3; transform: none; }
.next-button { min-height: 44px; padding: 0 16px; border-radius: 10px; color: #fff; background: var(--green); }
.next-button span { margin-left: 10px; }
.scene-dots { display: flex; gap: 7px; }
.scene-dot { width: 8px; height: 8px; padding: 0; border: 0; border-radius: 50%; background: #ccd0cc; }
.scene-dot.active { background: var(--green); transform: scale(1.3); }
.completion-message { margin: 16px 0 0; padding: 14px; border-radius: 10px; color: var(--green); background: var(--green-soft); font-size: 12px; font-weight: 700; line-height: 1.55; }

.metrics-card { display: grid; grid-template-columns: minmax(220px, 0.7fr) 1.3fr; gap: 30px; align-items: center; margin-top: 22px; padding: 26px 32px; }
.metrics-card dl { display: grid; grid-template-columns: repeat(5, 1fr); gap: 10px; margin: 0; }
.metrics-card dl div { padding-left: 13px; border-left: 1px solid var(--line); }
.metrics-card dt { color: var(--muted); font-size: 10px; }
.metrics-card dd { margin: 5px 0 0; font-size: 14px; font-weight: 800; }

.lessons-page { padding-bottom: 30px; }
.lessons-hero { display: grid; grid-template-columns: minmax(0, 1.25fr) minmax(290px, 0.75fr); gap: clamp(28px, 6vw, 80px); align-items: end; padding: clamp(52px, 8vw, 96px) 0 36px; }
.lessons-hero h1 { margin: 0; font-family: Georgia, "Noto Serif KR", serif; font-size: clamp(40px, 6vw, 68px); font-weight: 500; letter-spacing: -0.045em; line-height: 1.08; }
.lesson-summary { padding: 25px 27px; }
.lesson-summary span, .lesson-summary strong { display: block; }
.lesson-summary span { color: var(--green); font-size: 10px; font-weight: 800; letter-spacing: 0.1em; }
.lesson-summary strong { margin-top: 9px; font-family: Georgia, "Noto Serif KR", serif; font-size: 21px; }
.lesson-summary p { margin: 12px 0 0; color: var(--muted); font-size: 12px; line-height: 1.7; }

.lesson-overview { display: grid; grid-template-columns: minmax(230px, 0.56fr) minmax(0, 1.44fr); gap: 22px; }
.lesson-path, .lesson-course { padding: clamp(24px, 3.5vw, 36px); }
.lesson-path h2, .lesson-course h2, .lesson-player-heading h2, .lesson-complete h2 { margin: 0; font-family: Georgia, "Noto Serif KR", serif; font-size: clamp(26px, 3vw, 34px); font-weight: 500; }
.lesson-path ol { display: grid; gap: 0; margin: 27px 0 0; padding: 0; list-style: none; }
.lesson-path li { position: relative; display: grid; grid-template-columns: 36px 1fr; gap: 13px; align-items: center; min-height: 70px; color: var(--muted); }
.lesson-path li:not(:last-child)::after { position: absolute; top: 53px; bottom: -17px; left: 17px; width: 1px; content: ""; background: var(--line); }
.lesson-path li > span { position: relative; z-index: 1; display: grid; width: 36px; height: 36px; place-items: center; border: 1px solid var(--line); border-radius: 50%; background: var(--card); font-family: Georgia, serif; font-weight: 700; }
.lesson-path li strong, .lesson-path li small { display: block; }
.lesson-path li small { margin-top: 4px; font-size: 10px; }
.lesson-path li.current { color: var(--ink); }
.lesson-path li.current > span { border-color: var(--green); color: #fff; background: var(--green); }

.lesson-course-header { display: grid; grid-template-columns: 1fr auto; gap: 24px; align-items: start; }
.lesson-course-header p:last-child { max-width: 660px; margin: 13px 0 0; color: var(--muted); font-size: 13px; line-height: 1.7; }
.course-mark { display: grid; width: 66px; height: 66px; place-items: center; border-radius: 18px; color: #fff; background: var(--green-dark); font-family: Georgia, serif; font-size: 22px; }
.lesson-list { display: grid; gap: 10px; margin-top: 28px; }
.lesson-catalog-status { margin: 22px 0 0; color: var(--muted); font-size: 12px; line-height: 1.6; }
.lesson-tile { display: grid; grid-template-columns: auto 1fr auto; gap: 15px; align-items: center; width: 100%; min-height: 72px; padding: 12px 15px; border: 1px solid var(--line); border-radius: 14px; color: var(--ink); background: #faf8f1; text-align: left; }
.lesson-tile.available { border-color: #b8cdbf; background: var(--green-soft); }
.lesson-tile.available:hover { border-color: var(--green); transform: translateY(-1px); }
.lesson-tile.completed { background: #edf4ef; }
.lesson-tile:disabled { cursor: default; opacity: 0.55; }
.lesson-tile-number { display: grid; width: 42px; height: 42px; place-items: center; border-radius: 12px; color: var(--muted); background: #fff; font-family: Georgia, serif; font-size: 16px; font-weight: 700; }
.lesson-tile.available .lesson-tile-number { color: #fff; background: var(--green); }
.lesson-tile strong, .lesson-tile small { display: block; }
.lesson-tile small { margin-top: 5px; color: var(--muted); font-size: 10px; }
.lesson-tile-status { color: var(--green); font-size: 11px; font-weight: 800; }

.lesson-player { padding-top: 74px; scroll-margin-top: 74px; }
.lesson-player-heading { display: flex; align-items: end; justify-content: space-between; gap: 24px; margin-bottom: 20px; }
.lesson-layout { display: grid; grid-template-columns: minmax(0, 1.04fr) minmax(340px, 0.96fr); gap: 22px; }
.lesson-board-panel, .lesson-coach { min-width: 0; padding: clamp(20px, 3vw, 34px); }
.lesson-board-meta { display: flex; align-items: center; justify-content: space-between; gap: 18px; color: var(--muted); font-size: 11px; }
.lesson-board-meta span { color: var(--green); font-weight: 800; }
.lesson-board-meta strong { text-align: right; }
.lesson-coach { display: flex; flex-direction: column; }
.lesson-message { margin-top: 26px; }
.lesson-message h3 { margin: 0; font-family: Georgia, "Noto Serif KR", serif; font-size: clamp(21px, 2.4vw, 28px); font-weight: 500; line-height: 1.45; }
.lesson-message p:last-child { margin: 12px 0 0; color: var(--muted); font-family: inherit; font-size: 13px; line-height: 1.7; }
.lesson-options { display: grid; gap: 9px; margin-top: 22px; }
.lesson-option { display: grid; grid-template-columns: 30px 1fr; gap: 11px; align-items: center; min-height: 54px; padding: 9px 13px; border: 1px solid var(--line); border-radius: 11px; color: var(--ink); background: #fbfaf5; text-align: left; }
.lesson-option > span { display: grid; width: 28px; height: 28px; place-items: center; border-radius: 8px; color: var(--muted); background: #ecebe5; font-size: 11px; font-weight: 800; }
.lesson-option strong { font-size: 12px; line-height: 1.45; }
.lesson-option:not(:disabled):hover { border-color: var(--green); background: #fff; }
.lesson-option.correct { border-color: #79a18c; background: var(--green-soft); }
.lesson-option.correct > span { color: #fff; background: var(--green); }
.lesson-option.wrong { border-color: #d5a39d; background: #fae9e6; }
.lesson-option.wrong > span { color: #fff; background: var(--rose); }
.lesson-option:disabled { cursor: default; }
.lesson-feedback { margin-top: 13px; padding: 13px 15px; border-radius: 10px; font-size: 12px; font-weight: 700; line-height: 1.6; }
.lesson-feedback.correct { color: var(--green); background: var(--green-soft); }
.lesson-feedback.retry { color: #8a3933; background: #fae9e6; }
.lesson-hint-button { align-self: flex-start; margin-top: 13px; padding: 8px 0; border: 0; color: var(--green); background: transparent; font-size: 11px; font-weight: 800; }
.lesson-hint-button:hover:not(:disabled) { text-decoration: underline; }
.lesson-hint-button:disabled { cursor: default; opacity: 0.5; }
.lesson-hint-text { margin: 0; padding: 12px 14px; border-left: 3px solid #c5a85d; color: #655321; background: #fbf4dc; font-size: 12px; line-height: 1.6; }
.lesson-controls { display: flex; justify-content: space-between; gap: 12px; margin-top: auto; padding-top: 24px; }
.lesson-controls .primary-button:disabled { cursor: default; opacity: 0.42; }
.lesson-input-guide { align-self: center; max-width: 210px; color: var(--muted); font-size: 10px; line-height: 1.5; }
.square.lesson-square-action { cursor: pointer; }
.square.lesson-square-action:hover, .square.lesson-square-action:focus-visible { z-index: 1; outline: 3px solid #d0ad54; outline-offset: -3px; }
.square.lesson-square-action.selected-origin { z-index: 2; outline: 4px solid #28704d; outline-offset: -4px; }
.square.lesson-square-action.locked { cursor: default; }
.square.lesson-square-action.locked:hover { outline: none; }
.lesson-detail-card { padding: clamp(24px, 4vw, 38px); }
.lesson-detail-goal { max-width: 760px; margin: 10px 0 0; font-family: Georgia, "Noto Serif KR", serif; font-size: clamp(20px, 2.7vw, 28px); line-height: 1.55; }
.lesson-detail-meta { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 1px; margin: 28px 0 0; overflow: hidden; border: 1px solid var(--line); border-radius: 14px; background: var(--line); }
.lesson-detail-meta div { min-width: 0; padding: 16px; background: #fbfaf5; }
.lesson-detail-meta dt { color: var(--muted); font-size: 10px; font-weight: 800; }
.lesson-detail-meta dd { margin: 7px 0 0; overflow-wrap: anywhere; font-size: 13px; font-weight: 800; }
.lesson-detail-notice, .lesson-attempt-status { margin: 18px 0 0; color: var(--muted); font-size: 12px; line-height: 1.65; }
.lesson-detail-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 20px; }
.lesson-detail-actions button:disabled { cursor: default; opacity: 0.45; }
.lesson-attempt-status { color: var(--green); font-weight: 800; }

.lesson-complete { display: grid; grid-template-columns: auto 1fr auto; gap: 22px; align-items: center; margin-top: 26px; padding: clamp(24px, 4vw, 38px); }
.completion-check { display: grid; width: 56px; height: 56px; place-items: center; border-radius: 50%; color: #fff; background: var(--green); font-size: 24px; font-weight: 800; }
.lesson-complete p:not(.step-label) { margin: 10px 0 6px; color: var(--muted); font-size: 12px; }
.lesson-complete div > strong { font-family: Georgia, "Noto Serif KR", serif; font-size: 16px; line-height: 1.55; }

footer { display: flex; justify-content: space-between; gap: 24px; width: min(1180px, calc(100% - 40px)); margin: 60px auto 0; padding: 26px 0 38px; border-top: 1px solid rgba(22,35,28,0.12); color: var(--muted); font-size: 11px; }

@media (max-width: 900px) {
  .hero, .profile-strip, .setup-grid, .review-layout, .metrics-card, .lessons-hero, .lesson-overview, .lesson-layout { grid-template-columns: 1fr; }
  .hero { gap: 28px; padding-top: 64px; }
  .profile-form { grid-template-columns: 1fr 1fr; }
  .principle-card { display: none; }
  .metrics-card dl { grid-template-columns: repeat(3, 1fr); }
  .lesson-path ol { grid-template-columns: repeat(4, 1fr); gap: 10px; }
  .lesson-path li { grid-template-columns: 1fr; gap: 8px; justify-items: center; text-align: center; }
  .lesson-path li:not(:last-child)::after { top: 18px; right: -18px; bottom: auto; left: 50%; width: calc(100% + 26px); height: 1px; }
}

@media (max-width: 620px) {
  .site-header { padding-inline: 16px; }
  .brand small { display: none; }
  .header-tools { gap: 7px; }
  .system-status { display: none; }
  .account-controls { padding-left: 0; border-left: 0; }
  .account-controls span { max-width: 110px; }
  .status-pill { padding: 6px 8px; font-size: 9px; }
  main { width: min(100% - 24px, 1180px); }
  .app-navigation { width: 100%; }
  .app-nav-button { flex: 1; }
  .hero { padding: 48px 4px 32px; }
  .hero-copy { font-size: 14px; }
  .profile-strip { padding: 20px; border-radius: 16px; }
  .profile-form { grid-template-columns: 1fr; }
  .input-card, .board-panel, .coach-panel { padding: 20px; border-radius: 16px; }
  .section-heading, .analysis-header { align-items: flex-start; }
  .form-row { grid-template-columns: 1fr; gap: 0; }
  .form-actions { align-items: stretch; flex-direction: column; }
  .primary-button { width: 100%; }
  .analysis-section { padding-top: 58px; }
  .analysis-header { flex-direction: column; }
  .square { font-size: clamp(25px, 10vw, 42px); }
  .engine-strip div { padding: 10px 8px; }
  .engine-strip strong { font-size: 12px; }
  .coach-actions { grid-template-columns: 1fr; }
  .move-navigation { grid-template-columns: auto minmax(72px, 1fr) minmax(72px, 1fr) auto; }
  .move-navigation strong { grid-column: 1 / -1; grid-row: 1; }
  #firstMove { grid-column: 1; grid-row: 2; }
  #prevMove { grid-column: 2; grid-row: 2; }
  #nextMove { grid-column: 3; grid-row: 2; }
  #lastMove { grid-column: 4; grid-row: 2; }
  .metrics-card { padding: 22px; }
  .metrics-card dl { grid-template-columns: repeat(2, 1fr); }
  .lessons-hero { padding-top: 46px; }
  .lessons-hero h1 { font-size: clamp(36px, 12vw, 52px); }
  .lesson-path, .lesson-course, .lesson-board-panel, .lesson-coach { padding: 20px; border-radius: 16px; }
  .lesson-path ol { grid-template-columns: 1fr; }
  .lesson-path li { grid-template-columns: 36px 1fr; justify-items: stretch; text-align: left; }
  .lesson-path li:not(:last-child)::after { top: 53px; right: auto; bottom: -17px; left: 17px; width: 1px; height: auto; }
  .course-mark { width: 52px; height: 52px; border-radius: 14px; font-size: 18px; }
  .lesson-tile { grid-template-columns: auto 1fr; }
  .lesson-tile-status { grid-column: 2; }
  .lesson-player { padding-top: 54px; }
  .lesson-player-heading { align-items: flex-start; flex-direction: column; }
  .lesson-board-meta { align-items: flex-start; flex-direction: column; gap: 5px; }
  .lesson-board-meta strong { text-align: left; }
  .lesson-complete { grid-template-columns: auto 1fr; }
  .lesson-complete .secondary-button { grid-column: 1 / -1; }
  .lesson-detail-meta { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  footer { flex-direction: column; width: calc(100% - 24px); }
}