/* =========================================================================
   Apple-inspired design system applied to a utility app.
   SF Pro + single blue accent (#0066cc) + hairline borders + no shadows.
   ========================================================================= */

:root {
  /* Colors */
  --c-primary: #0066cc;
  --c-primary-focus: #0071e3;
  --c-primary-on-dark: #2997ff;

  --c-ink: #1d1d1f;
  --c-ink-muted-80: #333333;
  --c-ink-muted-48: #7a7a7a;
  --c-on-dark: #ffffff;
  --c-body-muted: #cccccc;

  --c-canvas: #ffffff;
  --c-parchment: #f5f5f7;
  --c-pearl: #fafafc;
  --c-tile-dark: #272729;
  --c-black: #000000;

  --c-hairline: #e0e0e0;
  --c-divider: #f0f0f0;

  --c-error: #d12022;
  --c-success-tint: rgba(0, 102, 204, 0.08);

  /* Radius */
  --r-none: 0;
  --r-sm: 8px;
  --r-md: 11px;
  --r-lg: 18px;
  --r-pill: 9999px;

  /* Spacing */
  --s-xxs: 4px;
  --s-xs: 8px;
  --s-sm: 12px;
  --s-md: 17px;
  --s-lg: 24px;
  --s-xl: 32px;
  --s-xxl: 48px;
  --s-section: 80px;

  /* Single shadow (reserved for photographic/product imagery if needed) */
  --shadow-product: rgba(0, 0, 0, 0.22) 3px 5px 30px 0;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }

body {
  font-family: "Pretendard Variable", Pretendard, system-ui, -apple-system,
    BlinkMacSystemFont, "Apple SD Gothic Neo", "맑은 고딕", "Malgun Gothic",
    "Segoe UI", sans-serif;
  font-size: 17px;
  font-weight: 400;
  line-height: 1.47;
  letter-spacing: -0.374px;
  color: var(--c-ink);
  background: var(--c-canvas);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.container { max-width: 1100px; margin: 0 auto; padding: 0 22px; }

/* ─── Global nav (Apple black bar) ────────────────────────────────────── */
.topbar {
  background: var(--c-black);
  color: var(--c-on-dark);
  height: 44px;
  position: sticky;
  top: 0;
  z-index: 100;
}
.topbar-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 44px;
}
.brand {
  color: var(--c-on-dark);
  font-size: 14px;
  font-weight: 400;
  letter-spacing: -0.224px;
  text-decoration: none;
  opacity: 0.92;
}
.brand:hover { opacity: 1; }
.topbar nav { display: flex; gap: 0; align-items: center; }
.topbar nav a {
  color: var(--c-on-dark);
  font-size: 12px;
  font-weight: 400;
  letter-spacing: -0.12px;
  text-decoration: none;
  padding: 0 14px;
  height: 44px;
  display: inline-flex;
  align-items: center;
  opacity: 0.85;
  transition: opacity .15s ease;
}
.topbar nav a:hover { opacity: 1; }
.topbar nav a.active { opacity: 1; }
.nav-logout { opacity: 0.65 !important; }

main {
  padding: 56px 0 96px;
  min-height: calc(100vh - 44px - 80px);
}

/* ─── Page head ───────────────────────────────────────────────────────── */
.page-head { margin-bottom: 48px; }
.page-head h1 {
  font-family: "Pretendard Variable", Pretendard, system-ui, -apple-system, sans-serif;
  font-size: 40px;
  font-weight: 600;
  line-height: 1.1;
  letter-spacing: -0.4px;
  color: var(--c-ink);
  margin: 8px 0 14px;
}
.page-head .muted {
  font-size: 21px;
  font-weight: 400;
  line-height: 1.29;
  letter-spacing: 0;
  color: var(--c-ink-muted-48);
  margin: 0;
}
.page-head .muted strong {
  color: var(--c-ink);
  font-weight: 600;
}
.crumbs {
  font-size: 14px;
  letter-spacing: -0.224px;
  color: var(--c-ink-muted-48);
  margin-bottom: 4px;
}
.crumbs a {
  color: var(--c-primary);
  text-decoration: none;
}
.crumbs a:hover { text-decoration: underline; }

/* ─── Track card grid (home) ──────────────────────────────────────────── */
.track-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
  gap: 16px;
}
.track-card {
  display: block;
  background: var(--c-canvas);
  border: 1px solid var(--c-hairline);
  border-radius: var(--r-lg);
  padding: 24px;
  text-decoration: none;
  color: var(--c-ink);
  transition: transform .15s ease, border-color .15s ease;
}
.track-card:hover {
  border-color: var(--c-primary);
}
.track-card:active {
  transform: scale(0.98);
}
.track-name {
  font-family: "Pretendard Variable", Pretendard, system-ui, sans-serif;
  font-size: 21px;
  font-weight: 600;
  line-height: 1.19;
  letter-spacing: 0;
  margin-bottom: 4px;
}
.track-meta {
  font-size: 14px;
  letter-spacing: -0.224px;
  color: var(--c-ink-muted-48);
  margin-bottom: 18px;
}

.bar-row {
  display: grid;
  grid-template-columns: 110px 1fr 44px;
  align-items: center;
  gap: 12px;
  margin-top: 10px;
  font-size: 12px;
  letter-spacing: -0.12px;
}
.bar-label { color: var(--c-ink-muted-48); }
.bar {
  height: 4px;
  background: var(--c-divider);
  border-radius: var(--r-pill);
  overflow: hidden;
}
.bar-fill {
  height: 100%;
  background: var(--c-primary);
  border-radius: var(--r-pill);
  transition: width .3s ease;
}
/* Apple: one accent only. Both bars share --c-primary. */
.bar-fill.alt { background: var(--c-primary); opacity: 0.7; }
.bar-pct { text-align: right; color: var(--c-ink-muted-48); }

/* ─── Sessions table ─────────────────────────────────────────────────── */
table.sessions {
  width: 100%;
  border-collapse: collapse;
  background: var(--c-canvas);
  border: 1px solid var(--c-hairline);
  border-radius: var(--r-lg);
  overflow: hidden;
}
table.sessions th, table.sessions td {
  padding: 14px 18px;
  border-bottom: 1px solid var(--c-divider);
  font-size: 14px;
  letter-spacing: -0.224px;
  text-align: left;
}
table.sessions th {
  background: var(--c-canvas);
  font-weight: 600;
  color: var(--c-ink-muted-48);
  font-size: 12px;
  letter-spacing: -0.12px;
  text-transform: none;
}
table.sessions td { color: var(--c-ink); }
table.sessions tr:last-child td { border-bottom: none; }
table.sessions tbody tr { transition: background .12s ease; }
table.sessions tbody tr:hover td { background: var(--c-pearl); }
.num { text-align: right; white-space: nowrap; }

.dot {
  display: inline-block;
  width: 6px; height: 6px;
  border-radius: 50%;
  margin-right: 6px;
  vertical-align: middle;
}
.dot.done { background: var(--c-primary); }
.dot.todo { background: var(--c-hairline); }

.pct {
  display: inline-block;
  margin-left: 8px;
  padding: 2px 10px;
  border-radius: var(--r-pill);
  font-size: 12px;
  font-weight: 400;
  letter-spacing: -0.12px;
}
.pct.ok  { background: var(--c-success-tint); color: var(--c-primary); }
.pct.mid { background: var(--c-divider);      color: var(--c-ink-muted-80); }
.pct.no  { background: var(--c-pearl);        color: var(--c-ink-muted-48); }

/* ─── Slot grid (upload sections) ────────────────────────────────────── */
.slot-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}
.slot-grid.compact { gap: 16px; }
@media (max-width: 720px) {
  .slot-grid { grid-template-columns: 1fr; }
}
.slot {
  background: var(--c-canvas);
  border: 1px solid var(--c-hairline);
  border-radius: var(--r-lg);
  padding: 32px;
}
.slot h2 {
  font-family: "Pretendard Variable", Pretendard, system-ui, sans-serif;
  font-size: 24px;
  font-weight: 600;
  letter-spacing: 0;
  margin: 0 0 20px;
}
.slot h3, .slot h4 {
  font-size: 17px;
  font-weight: 600;
  letter-spacing: -0.374px;
  margin: 0 0 12px;
}

.empty-slot {
  font-size: 14px;
  letter-spacing: -0.224px;
  color: var(--c-ink-muted-48);
  font-style: normal;
  padding: 0;
  margin: 0 0 20px;
}
.hint-note {
  font-size: 13px;
  letter-spacing: -0.16px;
  color: var(--c-ink-muted-48);
  background: var(--c-pearl);
  border: 1px solid var(--c-divider);
  border-radius: var(--r-sm);
  padding: 10px 14px;
  margin: 0 0 14px;
}

/* ─── File list ──────────────────────────────────────────────────────── */
.file-list { list-style: none; padding: 0; margin: 0 0 24px; }
.file-list li {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 12px;
  padding: 14px 0;
  border-bottom: 1px solid var(--c-divider);
}
.file-list li:last-child { border-bottom: none; }
.file-link, .file-list a {
  color: var(--c-primary);
  text-decoration: none;
  font-size: 17px;
  letter-spacing: -0.374px;
  word-break: break-all;
}
.file-list a:hover { text-decoration: underline; }
.file-name {
  color: var(--c-ink);
  font-size: 17px;
  letter-spacing: -0.374px;
  word-break: break-all;
}
.file-meta {
  grid-column: 1 / -1;
  font-size: 12px;
  letter-spacing: -0.12px;
  color: var(--c-ink-muted-48);
}
.btn-del {
  background: transparent;
  border: 1px solid var(--c-hairline);
  color: var(--c-ink-muted-80);
  padding: 6px 14px;
  border-radius: var(--r-sm);
  cursor: pointer;
  font-size: 14px;
  letter-spacing: -0.224px;
  font-family: inherit;
  transition: transform .1s ease, border-color .15s, color .15s;
  grid-row: 1 / 2;
  grid-column: 2 / 3;
}
.btn-del:hover { border-color: var(--c-ink); color: var(--c-ink); }
.btn-del:active { transform: scale(0.95); }

/* ─── Forms / upload ─────────────────────────────────────────────────── */
.upload-form { margin-top: 8px; }
.field { display: block; margin-bottom: 16px; }
.field span {
  display: block;
  font-size: 14px;
  letter-spacing: -0.224px;
  color: var(--c-ink-muted-48);
  margin-bottom: 6px;
}
.field input[type=text],
.login-form input[type=password] {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--c-hairline);
  border-radius: var(--r-md);
  font-size: 17px;
  letter-spacing: -0.374px;
  background: var(--c-canvas);
  font-family: inherit;
  color: var(--c-ink);
  transition: border-color .15s ease;
}
.field input[type=text]:focus,
.login-form input[type=password]:focus {
  outline: 2px solid var(--c-primary-focus);
  outline-offset: 0;
  border-color: var(--c-primary-focus);
}

.filedrop {
  position: relative;
  border: 2px dashed var(--c-hairline);
  border-radius: var(--r-lg);
  padding: 36px 24px;
  text-align: center;
  background: var(--c-pearl);
  margin-bottom: 12px;
  transition: border-color .15s, background .15s;
}
.filedrop:hover,
.filedrop.dragging {
  border-color: var(--c-primary);
  background: var(--c-success-tint);
}
.filedrop-input {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  opacity: 0;
  cursor: pointer;
  z-index: 1;
}
.filedrop-content {
  pointer-events: none;
  display: flex;
  flex-direction: column;
  gap: 4px;
}
.filedrop-title {
  font-size: 15px;
  font-weight: 600;
  letter-spacing: -0.224px;
  color: var(--c-ink);
}
.filedrop-hint {
  font-size: 12px;
  letter-spacing: -0.12px;
  color: var(--c-ink-muted-48);
}
.filedrop-selected {
  list-style: none;
  margin: 0 0 12px;
  padding: 12px 16px;
  background: var(--c-pearl);
  border: 1px solid var(--c-divider);
  border-radius: var(--r-md);
  font-size: 14px;
  letter-spacing: -0.224px;
}
.filedrop-selected li {
  padding: 4px 0;
  color: var(--c-ink-muted-80);
  word-break: break-all;
}
.filedrop-selected li + li {
  border-top: 1px solid var(--c-divider);
}
.filedrop-error {
  color: var(--c-error);
  font-size: 14px;
  letter-spacing: -0.224px;
  margin: 0 0 12px;
}
.btn-primary:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

/* ─── Buttons ────────────────────────────────────────────────────────── */
.btn-primary {
  display: inline-block;
  background: var(--c-primary);
  color: var(--c-on-dark);
  border: 1px solid var(--c-primary);
  padding: 11px 22px;
  border-radius: var(--r-pill);
  text-decoration: none;
  font-size: 17px;
  letter-spacing: -0.374px;
  font-weight: 400;
  cursor: pointer;
  font-family: inherit;
  transition: transform .1s ease, background .15s, border-color .15s;
}
.btn-primary:hover {
  background: var(--c-primary-focus);
  border-color: var(--c-primary-focus);
}
.btn-primary:active { transform: scale(0.95); }
.btn-primary:focus-visible {
  outline: 2px solid var(--c-primary-focus);
  outline-offset: 2px;
}

.btn {
  display: inline-block;
  padding: 11px 22px;
  border-radius: var(--r-pill);
  border: 1px solid var(--c-primary);
  background: transparent;
  color: var(--c-primary);
  text-decoration: none;
  font-size: 17px;
  letter-spacing: -0.374px;
  font-weight: 400;
  cursor: pointer;
  font-family: inherit;
  transition: transform .1s ease, background .15s;
}
.btn:hover { background: var(--c-success-tint); }
.btn:active { transform: scale(0.95); }

.btn-sm {
  display: inline-block;
  padding: 6px 14px;
  border-radius: var(--r-pill);
  border: 1px solid var(--c-hairline);
  background: transparent;
  color: var(--c-primary);
  text-decoration: none;
  font-size: 14px;
  letter-spacing: -0.224px;
  font-weight: 400;
  margin-right: 4px;
  cursor: pointer;
  font-family: inherit;
  transition: transform .1s ease, background .15s, border-color .15s;
}
.btn-sm:hover {
  background: var(--c-pearl);
  border-color: var(--c-primary);
}
.btn-sm:active { transform: scale(0.95); }

/* ─── Admin ──────────────────────────────────────────────────────────── */
.stats {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 16px;
  margin-bottom: 32px;
}
.stat {
  background: var(--c-canvas);
  border: 1px solid var(--c-hairline);
  border-radius: var(--r-lg);
  padding: 24px;
}
.stat-num {
  font-family: "Pretendard Variable", Pretendard, system-ui, sans-serif;
  font-size: 34px;
  font-weight: 600;
  letter-spacing: -0.374px;
  line-height: 1.1;
  color: var(--c-ink);
}
.stat-label {
  font-size: 14px;
  letter-spacing: -0.224px;
  color: var(--c-ink-muted-48);
  margin-top: 6px;
}

.admin-actions {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
  margin-bottom: 32px;
}

.admin-session {
  background: var(--c-canvas);
  border: 1px solid var(--c-hairline);
  border-radius: var(--r-lg);
  padding: 32px;
  margin-bottom: 16px;
}
.admin-session h3 {
  font-family: "Pretendard Variable", Pretendard, system-ui, sans-serif;
  font-size: 21px;
  font-weight: 600;
  letter-spacing: 0;
  margin: 0 0 18px;
}
.admin-session h3 .muted {
  font-weight: 400;
  color: var(--c-ink-muted-48);
  font-size: 17px;
  letter-spacing: -0.374px;
}
.admin-session .slot {
  padding: 20px;
  border-color: var(--c-divider);
}

/* ─── Login ──────────────────────────────────────────────────────────── */
.login-box {
  max-width: 420px;
  margin: 80px auto;
  background: var(--c-canvas);
  border: 1px solid var(--c-hairline);
  border-radius: var(--r-lg);
  padding: 48px;
}
.login-box h1 {
  font-family: "Pretendard Variable", Pretendard, system-ui, sans-serif;
  font-size: 28px;
  font-weight: 600;
  letter-spacing: -0.28px;
  margin: 0 0 6px;
}
.login-box > .muted {
  font-size: 17px;
  letter-spacing: -0.374px;
  color: var(--c-ink-muted-48);
  margin: 0 0 28px;
}
.login-form .field { margin-bottom: 20px; }
.login-form button {
  width: 100%;
  padding: 12px;
  font-size: 17px;
}
.small-note {
  font-size: 12px;
  letter-spacing: -0.12px;
  color: var(--c-ink-muted-48);
  margin-top: 28px;
  line-height: 1.5;
}

/* ─── Footer ─────────────────────────────────────────────────────────── */
footer {
  background: var(--c-parchment);
  color: var(--c-ink-muted-48);
  padding: 32px 0 40px;
  text-align: center;
  font-size: 12px;
  letter-spacing: -0.12px;
  margin-top: 80px;
}
footer small { font-size: inherit; }

/* ─── Utility ────────────────────────────────────────────────────────── */
.muted { color: var(--c-ink-muted-48); }
.empty {
  text-align: center;
  padding: 80px 32px;
  color: var(--c-ink-muted-48);
  background: var(--c-canvas);
  border: 1px solid var(--c-hairline);
  border-radius: var(--r-lg);
  font-size: 17px;
}
code {
  background: var(--c-pearl);
  padding: 2px 8px;
  border-radius: var(--r-sm);
  font-family: "SF Mono", Menlo, Consolas, monospace;
  font-size: 90%;
  border: 1px solid var(--c-divider);
}
.error-message {
  color: var(--c-error);
  font-weight: 400;
  font-size: 14px;
  letter-spacing: -0.224px;
}

/* ─── Reduce motion ──────────────────────────────────────────────────── */
@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; animation: none !important; }
}