/* ==========================================================================
   데이터통계분석 — 수업 홈
   Direction: Swiss editorial. 종이(paper) 바탕 · 잉크 위계 · 버밀리언 단일 액센트.
   ========================================================================== */

:root {
  /* --- color --------------------------------------------------------- */
  --paper:        oklch(97.5% 0.008 85);
  --paper-deep:   oklch(94.5% 0.012 85);
  --ink:          oklch(21% 0.015 265);
  --ink-soft:     oklch(45% 0.012 265);
  --ink-faint:    oklch(66% 0.010 265);
  --rule:         oklch(86% 0.010 265);
  --rule-strong:  oklch(72% 0.012 265);
  --accent:       oklch(56% 0.192 32);
  --accent-soft:  oklch(56% 0.192 32 / 0.10);
  --locked-bar:   oklch(88% 0.008 265);

  /* --- type ---------------------------------------------------------- */
  --font-display: "Iowan Old Style", "Palatino Linotype", "Times New Roman", ui-serif, Georgia, serif;
  --font-sans: -apple-system, BlinkMacSystemFont, "Pretendard", "Apple SD Gothic Neo",
               "Malgun Gothic", "Noto Sans KR", system-ui, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;

  --text-hero:  clamp(2.6rem, 1.2rem + 5.6vw, 6.5rem);
  --text-lead:  clamp(1rem, 0.94rem + 0.3vw, 1.15rem);
  --text-row:   clamp(1.05rem, 0.9rem + 0.7vw, 1.6rem);
  --text-no:    clamp(1.3rem, 1rem + 1.4vw, 2.4rem);
  --text-micro: 0.72rem;

  /* --- rhythm -------------------------------------------------------- */
  --gutter: clamp(1.25rem, 0.6rem + 3vw, 5rem);
  --stack:  clamp(3rem, 2rem + 4vw, 7rem);

  --dur: 420ms;
  --ease: cubic-bezier(0.16, 1, 0.3, 1);
}

*, *::before, *::after { box-sizing: border-box; }

html { -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  min-height: 100dvh;
  font-family: var(--font-sans);
  color: var(--ink);
  background-color: var(--paper);
  /* 종이 질감: 아주 옅은 수직 괘선 + 노이즈 */
  background-image:
    repeating-linear-gradient(90deg,
      oklch(21% 0.015 265 / 0.02) 0 1px, transparent 1px 96px),
    url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='140' height='140'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='3'/%3E%3C/filter%3E%3Crect width='140' height='140' filter='url(%23n)' opacity='0.035'/%3E%3C/svg%3E");
  line-height: 1.55;
  letter-spacing: -0.005em;
  -webkit-font-smoothing: antialiased;
}

a { color: inherit; }

.shell {
  max-width: 1180px;
  margin-inline: auto;
  padding-inline: var(--gutter);
}

/* ==========================================================================
   Masthead
   ========================================================================== */

.masthead {
  padding-block: clamp(2.5rem, 1.5rem + 4vw, 6rem) 0;
}

.masthead__kicker {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0.75rem 1.25rem;
  font-size: var(--text-micro);
  letter-spacing: 0.22em;
  text-transform: uppercase;
  color: var(--ink-soft);
  font-weight: 600;
  padding-bottom: 1.1rem;
  border-bottom: 1px solid var(--ink);
}

.masthead__kicker .dot {
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--accent);
  display: inline-block;
  translate: 0 -2px;
}

.masthead__title {
  margin: clamp(1.5rem, 1rem + 2vw, 3rem) 0 0;
  font-size: var(--text-hero);
  font-weight: 800;
  line-height: 0.94;
  letter-spacing: -0.045em;
}

.masthead__latin {
  display: block;
  font-family: var(--font-display);
  font-weight: 400;
  font-style: italic;
  font-size: clamp(1.1rem, 0.7rem + 1.6vw, 2.2rem);
  letter-spacing: -0.01em;
  color: var(--ink-faint);
  margin-top: 0.6rem;
}

/* 진행 상황 — 15칸 눈금 */
.progress {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-end;
  gap: clamp(1rem, 0.5rem + 2vw, 2.5rem);
  margin-top: clamp(2rem, 1.4rem + 2vw, 3.5rem);
  padding-bottom: clamp(2rem, 1.4rem + 2vw, 3.25rem);
}

.progress__ticks {
  display: grid;
  grid-template-columns: repeat(15, minmax(0, 1fr));
  gap: 4px;
  flex: 1 1 320px;
  min-width: 220px;
}

.progress__tick {
  height: 34px;
  background: var(--paper-deep);
  border-bottom: 2px solid var(--rule-strong);
}

.progress__tick[data-state="open"] {
  background: var(--accent);
  border-bottom-color: var(--accent);
}

.progress__read {
  font-family: var(--font-display);
  font-size: clamp(1rem, 0.8rem + 0.9vw, 1.4rem);
  color: var(--ink-soft);
  white-space: nowrap;
}

.progress__read b {
  font-weight: 700;
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}

.masthead__note {
  font-size: var(--text-lead);
  color: var(--ink-soft);
  max-width: 46ch;
  margin: 0;
}

/* ==========================================================================
   Index — 주차 목록
   ========================================================================== */

.index {
  margin-top: clamp(1.5rem, 1rem + 2vw, 3rem);
  border-top: 2px solid var(--ink);
}

.index__head {
  display: grid;
  grid-template-columns: 5.5rem 1fr auto;
  gap: 1.5rem;
  padding: 0.7rem 0;
  border-bottom: 1px solid var(--rule);
  font-size: var(--text-micro);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--ink-faint);
  font-weight: 600;
}

.row {
  display: grid;
  grid-template-columns: 5.5rem 1fr auto;
  gap: 1.5rem;
  align-items: center;
  padding: clamp(1rem, 0.7rem + 0.8vw, 1.6rem) 0;
  border-bottom: 1px solid var(--rule);
  position: relative;
  text-decoration: none;
}

.row::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 calc(var(--gutter) * -1);
  width: 3px;
  background: var(--accent);
  scale: 1 0;
  transform-origin: 50% 100%;
  transition: scale var(--dur) var(--ease);
}

.row__no {
  font-family: var(--font-display);
  font-size: var(--text-no);
  font-weight: 400;
  font-variant-numeric: tabular-nums;
  color: var(--ink-faint);
  line-height: 1;
  letter-spacing: -0.02em;
}

.row__title {
  font-size: var(--text-row);
  font-weight: 650;
  letter-spacing: -0.025em;
  line-height: 1.25;
  margin: 0;
}

.row__meta {
  display: flex;
  align-items: center;
  gap: 0.55rem;
  flex-wrap: wrap;
  margin-top: 0.45rem;
}

.tag {
  font-size: var(--text-micro);
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--ink-soft);
  border: 1px solid var(--rule-strong);
  border-radius: 2px;
  padding: 0.15rem 0.45rem;
  font-family: var(--font-mono);
}

.row__state {
  font-size: var(--text-micro);
  letter-spacing: 0.16em;
  text-transform: uppercase;
  font-weight: 700;
  color: var(--ink-faint);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  white-space: nowrap;
}

/* --- 열린 주차 -------------------------------------------------------- */

.row--open { color: var(--ink); }
.row--open .row__no { color: var(--accent); font-weight: 700; }
.row--open .row__state { color: var(--accent); }

.row--open .row__arrow {
  width: 1.4rem; height: 1.4rem;
  display: grid; place-items: center;
  transition: translate var(--dur) var(--ease);
}

@media (hover: hover) {
  .row--open:hover::before { scale: 1 1; }
  .row--open:hover .row__title { translate: 6px 0; }
  .row--open:hover .row__arrow { translate: 5px 0; }
  .row--open .row__title { transition: translate var(--dur) var(--ease); }
}

.row--open:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 4px;
}

/* --- 잠긴 주차: 제목은 빈 값 ------------------------------------------ */

.row--locked { cursor: not-allowed; }

.row--locked .row__no { color: var(--rule-strong); }

.row__redacted {
  display: block;
  height: 0.9em;
  max-width: min(100%, 22rem);
  background: repeating-linear-gradient(
    -45deg,
    var(--locked-bar) 0 6px,
    oklch(92% 0.006 265) 6px 12px
  );
  border-radius: 1px;
}

.row--locked .row__state { color: var(--ink-faint); opacity: 0.75; }

/* ==========================================================================
   Week detail
   ========================================================================== */

.back {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  margin-top: clamp(2rem, 1.5rem + 2vw, 3.5rem);
  font-size: var(--text-micro);
  letter-spacing: 0.18em;
  text-transform: uppercase;
  font-weight: 700;
  color: var(--ink-soft);
  text-decoration: none;
}
.back:hover { color: var(--accent); }

.detail__head {
  margin-top: 1.75rem;
  padding-bottom: clamp(1.5rem, 1rem + 2vw, 2.5rem);
  border-bottom: 2px solid var(--ink);
}

.detail__no {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(3rem, 1.5rem + 6vw, 7rem);
  line-height: 0.9;
  color: var(--accent);
  font-variant-numeric: tabular-nums;
  letter-spacing: -0.04em;
}

.detail__title {
  margin: 0.5rem 0 0;
  font-size: clamp(1.7rem, 1rem + 3vw, 3.4rem);
  font-weight: 800;
  letter-spacing: -0.04em;
  line-height: 1.08;
}

.files {
  list-style: none;
  margin: 0;
  padding: 0;
}

.file {
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 1.25rem;
  align-items: center;
  padding: clamp(1rem, 0.8rem + 0.6vw, 1.5rem) 0;
  border-bottom: 1px solid var(--rule);
  text-decoration: none;
  position: relative;
}

.file-row {
  border-bottom: 1px solid var(--rule);
}

.file-row .file { border-bottom: none; }

/* 원본 PDF 내려받기 — 슬라이드가 주 동선이고 이쪽은 보조 */
.file__alt {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  margin: 0 0 1rem calc(2.6rem + 1.25rem);
  font-size: var(--text-micro);
  font-family: var(--font-mono);
  letter-spacing: 0.04em;
  color: var(--ink-faint);
  text-decoration: none;
}
.file__alt:hover { color: var(--accent); }
.file__alt:focus-visible { outline: 2px solid var(--accent); outline-offset: 3px; }

.file__kind {
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  font-weight: 700;
  letter-spacing: 0.08em;
  padding: 0.3rem 0.5rem;
  border: 1px solid var(--ink);
  border-radius: 2px;
  background: var(--ink);
  color: var(--paper);
}
.file__kind[data-kind="SLIDES"] { background: var(--accent); border-color: var(--accent); }
.file__kind[data-kind="PDF"] { background: var(--ink); border-color: var(--ink); }
.file__kind[data-kind="ZIP"], .file__kind[data-kind="CSV"] {
  background: transparent; color: var(--ink-soft); border-color: var(--rule-strong);
}

.file__name {
  font-size: clamp(0.98rem, 0.9rem + 0.4vw, 1.2rem);
  font-weight: 600;
  letter-spacing: -0.02em;
  overflow-wrap: anywhere;
}

.file__size {
  font-family: var(--font-mono);
  font-size: var(--text-micro);
  color: var(--ink-faint);
  white-space: nowrap;
}

@media (hover: hover) {
  .file { transition: background var(--dur) var(--ease); }
  .file:hover { background: var(--accent-soft); }
  .file:hover .file__name { color: var(--accent); }
}
.file:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }

.empty {
  padding: 3rem 0;
  color: var(--ink-faint);
  font-size: var(--text-lead);
}

/* ==========================================================================
   Footer
   ========================================================================== */

.foot {
  margin-top: var(--stack);
  padding-block: 2rem 3.5rem;
  border-top: 1px solid var(--rule);
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem 1.5rem;
  justify-content: space-between;
  font-size: var(--text-micro);
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-faint);
  font-weight: 600;
}

/* ==========================================================================
   Motion — 로드 시 행 순차 노출
   ========================================================================== */

@media (prefers-reduced-motion: no-preference) {
  .reveal {
    opacity: 0;
    translate: 0 14px;
    animation: rise 620ms var(--ease) forwards;
    animation-delay: calc(var(--i, 0) * 42ms);
  }
  @keyframes rise {
    to { opacity: 1; translate: 0 0; }
  }
}

/* ==========================================================================
   Narrow screens
   ========================================================================== */

@media (max-width: 640px) {
  .index__head { display: none; }

  .row {
    grid-template-columns: 3.2rem 1fr;
    grid-template-areas: "no title" ".  state";
    gap: 0.5rem 1rem;
  }
  .row__no    { grid-area: no; }
  .row__body  { grid-area: title; }
  .row__state { grid-area: state; }

  /* 잠긴 행은 표시할 제목이 없으므로 한 줄로 붙인다 */
  .row--locked {
    grid-template-columns: 3.2rem 1fr auto;
    grid-template-areas: "no title state";
    align-items: center;
  }

  .file { grid-template-columns: auto 1fr; }
  .file__size { grid-column: 2; font-size: 0.68rem; }
  .file__alt { margin-left: 0; }
}