:root {
  --brand: #2878d4;
  --brand-strong: #2065b4;
  --brand-soft: #eaf2ff;
  --brand-softer: #f3f8fc;
  --ink: #22303f;
  --ink-2: #5b6b7e;
  --ink-3: #7a8795;
  --line: #e2e8f0;
  --line-strong: #d5dbe3;
  --bg: #f0f2f8;
  --surface: #ffffff;
  --danger: #b42318;
  --danger-strong: #a62f25;
  --danger-soft: #fff4f2;
  --danger-line: #e8bcbc;
  --success: #047857;
  --r-sm: 8px;
  --r-md: 12px;
  --r-lg: 18px;
  --sp-1: 4px;
  --sp-2: 8px;
  --sp-3: 12px;
  --sp-4: 16px;
  --sp-5: 24px;
  --sp-6: 32px;
  --control-h: 44px;
  --font: -apple-system, BlinkMacSystemFont, "Apple SD Gothic Neo", sans-serif;
}

* { box-sizing: border-box; }
html, body { margin: 0; }
body {
  min-height: 100vh;
  font-family: var(--font);
  color: var(--ink);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 { margin: 0; letter-spacing: -.02em; color: var(--ink); }
h1 { font-size: 32px; line-height: 1.25; }
h2 { font-size: 22px; line-height: 1.3; }
h3 { font-size: 17px; line-height: 1.35; }
p { margin: 0; }
a { color: var(--brand); text-underline-offset: 3px; }

.hidden { display: none !important; }
.muted { color: var(--ink-2); line-height: 1.6; }
small, .fine-print { color: var(--ink-3); font-size: 13px; line-height: 1.6; }
.eyebrow { color: var(--brand); font-size: 11px; font-weight: 800; letter-spacing: .12em; text-transform: uppercase; margin: 0 0 8px; }

.card {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  padding: 24px;
}

.brand-logo { display: block; object-fit: contain; border-radius: 0; }

button { font: inherit; -webkit-appearance: none; appearance: none; border: 0; background: none; padding: 0; color: inherit; }
button:not(:disabled) { cursor: pointer; }
button:disabled { opacity: .5; cursor: not-allowed; }
summary { cursor: pointer; }

input, select, textarea {
  width: 100%;
  font: inherit;
  color: var(--ink);
  background: var(--surface);
  border: 1px solid var(--line-strong);
  border-radius: var(--r-sm);
  padding: 11px 12px;
  outline: none;
}
textarea { resize: vertical; font: 15px/1.7 ui-monospace, SFMono-Regular, Menlo, monospace; }
select { appearance: none; -webkit-appearance: none; padding-right: 32px; background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8'%3E%3Cpath fill='%237a8795' d='M6 8 0 0h12z'/%3E%3C/svg%3E"); background-repeat: no-repeat; background-position: right 12px center; }
input:focus, select:focus, textarea:focus { border-color: var(--brand); box-shadow: 0 0 0 3px rgba(40, 120, 212, .14); }
input[type="checkbox"], input[type="radio"] { width: auto; accent-color: var(--brand); }
input[type="file"] { padding: 8px; }

.primary, .secondary, .danger-button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: var(--control-h);
  padding: 0 18px;
  border-radius: var(--r-sm);
  font-weight: 700;
  text-decoration: none;
  transition: background .15s, border-color .15s, color .15s;
}
.primary { background: var(--brand); color: #fff; }
.primary:hover { background: var(--brand-strong); }
.secondary { background: var(--brand-softer); color: var(--brand-strong); }
.secondary:hover { background: #e3eefa; }
.danger-button { background: var(--danger-soft); color: var(--danger-strong); border: 1px solid var(--danger-line); }
.danger-button:hover { background: #fee8e5; }

.quiet-button {
  min-height: 32px;
  padding: 5px 12px;
  border: 1px solid #d9e1ea;
  border-radius: var(--r-sm);
  background: var(--surface);
  color: var(--ink-2);
  font-size: 13px;
  font-weight: 600;
  white-space: nowrap;
  transition: color .15s, border-color .15s, background .15s;
}
.quiet-button:hover:not(:disabled) { color: var(--danger); border-color: var(--danger-line); background: var(--danger-soft); }

:focus-visible { outline: 2px solid var(--brand); outline-offset: 2px; }

form { display: grid; gap: 16px; }
label { display: grid; gap: 7px; font-size: 13px; font-weight: 700; color: var(--ink-2); }

.message { min-height: 20px; margin: 12px 0 0; font-size: 13px; color: var(--danger); line-height: 1.5; }
.message:empty { display: none; }
.message.success { color: var(--success); }

.kakao { display: block; margin-top: 10px; border-radius: var(--r-sm); padding: 13px 16px; background: #fee500; color: #191600; text-align: center; text-decoration: none; font-weight: 700; }
.kakao:hover { filter: brightness(.98); }

.divider { display: flex; align-items: center; gap: 14px; color: var(--ink-3); font-size: 11px; margin: 20px 0 14px; }
.divider::before, .divider::after { content: ''; height: 1px; background: var(--line); flex: 1; }

fieldset.consents { border: 0; border-top: 1px solid var(--line); padding: 18px 0 0; margin: 8px 0; }
.consents legend { font-size: 12px; color: var(--ink-2); padding-right: 10px; }
.check-row { display: flex; align-items: flex-start; gap: 10px; margin: 12px 0; font-size: 12px; font-weight: 400; line-height: 1.7; color: var(--ink); }
.check-row input { width: 17px; height: 17px; flex-shrink: 0; margin: 2px 0; }
.check-row span { color: var(--ink-2); }

/* Login · signup */
.shell {
  width: min(1060px, calc(100% - 64px));
  min-height: 100vh;
  margin: 0 auto;
  padding: 64px 0;
  display: grid;
  grid-template-columns: 1fr 420px;
  gap: 96px;
  align-items: center;
}
.shell .hero { align-self: center; }
.shell .hero .brand-logo { width: 56px; height: 56px; margin-bottom: 36px; }
.shell .hero h1 { font-size: clamp(36px, 4vw, 54px); line-height: 1.28; font-weight: 750; margin: 24px 0; }
.shell .hero .muted { font-size: 17px; line-height: 1.9; }
.shell .hero .login-tagline { font-weight: 700; }
.shell > .card { padding: 36px; }
#auth-card > h2 { margin-bottom: 18px; }
#auth-form #password-label { margin-top: -6px; }
.auth-intro { font-size: 13px; color: var(--ink-3); line-height: 1.7; margin: 10px 0 28px; }
.auth-assist { margin: 13px 0 0; text-align: right; font-size: 12px; }
.auth-foot { text-align: center; font-size: 12px; color: var(--ink-2); margin: 26px 0 0; }
.auth-foot a { margin-left: 6px; font-weight: 600; }
#email-fields { display: grid; gap: 16px; }
#email-fields[hidden] { display: none; }

/* Study layout */
.study {
  width: min(1480px, calc(100% - 64px));
  margin: 0 auto 40px;
  display: grid;
  grid-template-columns: 240px 260px minmax(0, 1fr);
  gap: 24px;
  align-items: start;
}
.study h2 { font-size: 20px; margin-bottom: 20px; }
.list-item {
  display: block;
  width: 100%;
  text-align: left;
  padding: 12px;
  margin-top: 10px;
  border: 1px solid var(--line);
  background: var(--surface);
  border-radius: var(--r-sm);
  cursor: pointer;
  overflow-wrap: anywhere;
  font-size: 14px;
  line-height: 1.5;
  transition: background .15s, border-color .15s;
}
.list-item:hover { background: var(--brand-softer); border-color: #a6c9f0; }
.list-item[aria-pressed="true"] { background: var(--brand-soft); border-color: var(--brand); color: var(--brand-strong); font-weight: 700; }
#study-message { font-size: 13px; line-height: 1.6; color: var(--ink-2); }

/* Legal documents */
.legal {
  width: min(860px, calc(100% - 40px));
  margin: 36px auto 64px;
  padding: clamp(24px, 5vw, 52px);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: var(--surface);
  box-shadow: 0 12px 32px rgba(35, 48, 63, .045);
}
.legal-header{ max-width: 72ch; }
.legal-back{
  display: inline-flex;
  min-height: 38px;
  align-items: center;
  padding: 0 12px;
  border: 1px solid var(--line);
  border-radius: var(--r-sm);
  color: var(--ink-2);
  background: #fff;
  font-size: 13px;
  font-weight: 650;
  text-decoration: none;
}
.legal-back:hover{ color:var(--brand-strong); border-color:#bfd2ea; background:var(--brand-softer); }
.legal-header .eyebrow{ margin:28px 0 8px; }
.legal-header h1{ max-width:24ch; font-size:clamp(25px,4vw,32px); line-height:1.4; }
.legal-version{ display:flex; flex-wrap:wrap; gap:6px 12px; margin-top:14px; color:var(--ink-3); font-size:12px; }
.legal-version span{ color:var(--ink-2); }
.legal-notice{
  margin:20px 0 0;
  padding:14px 16px;
  border-left:3px solid #8aa4e2;
  border-radius:0 8px 8px 0;
  color:var(--ink-2);
  background:#f5f8fd;
  font-size:13px;
  line-height:1.75;
}
.legal-content{ max-width:72ch; margin-top:30px; }
.legal-content section{ padding:22px 0; border-top:1px solid #edf0f4; }
.legal-content h2{ margin:0 0 9px; color:var(--ink); font-size:18px; line-height:1.5; }
.legal-content p{ color:#526174; font-size:15px; line-height:1.9; overflow-wrap:anywhere; }

/* Profile (mypage) */
.profile { max-width: 760px; padding: 32px 20px 64px; margin: auto; }
.profile header { display: flex; align-items: center; justify-content: space-between; margin-bottom: 42px; font-size: 13px; }
.profile header a { text-decoration: none; }
.profile > .card { margin-top: 24px; }
.profile form { margin-top: 22px; }
.profile .secondary { margin-top: 18px; }
.profile-download { display: inline-block; margin-top: 20px; text-decoration: none; }
.storage-summary { display: grid; gap: 10px; margin: 18px 0; }
.storage-summary div { display: flex; justify-content: space-between; gap: 12px; font-size: 13px; }
.storage-summary span { color: var(--ink-2); }
.storage-summary progress { width: 100%; height: 10px; accent-color: var(--brand); }
.danger-zone { border-color: #efd1cd; }
.danger-zone summary { margin-top: 18px; color: var(--danger-strong); cursor: pointer; font-size: 13px; font-weight: 700; }
.danger-zone form { margin-top: 18px; }
.semester-row { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.schedule-row { padding: 12px 0; border-bottom: 1px solid var(--line); line-height: 1.8; }
.schedule-row span { font-size: 13px; color: var(--ink-2); }
.profile-link { display: inline-block; margin-left: 16px; font-size: 13px; }

/* Dialog */
dialog { width: min(400px, calc(100% - 40px)); padding: 30px; border: 1px solid #dce3ed; border-radius: var(--r-md); color: var(--ink); }
dialog::backdrop { background: #17283c55; }
dialog h2 { font-size: 22px; }
dialog p { font-size: 14px; line-height: 1.8; }
dialog a { display: block; text-align: center; text-decoration: none; margin: 24px 0 10px; }
#school-prompt:not([open]){ display:none; }
#school-prompt[open]{ display:grid; gap:12px; width:min(430px,calc(100% - 32px)); padding:28px; }
#school-prompt h2{ margin:0; }
#school-prompt p{ margin:0 0 4px; }
#school-prompt > a.primary,
#school-prompt > form,
#school-prompt > form button{ box-sizing:border-box; width:100%; margin:0; }
#school-prompt > a.primary,
#school-prompt > form button{ min-height:46px; }

@media (max-width: 850px) {
  .shell:not(.workspace-shell) { max-width: 460px; display: block; width: calc(100% - 32px); padding: 32px 0; }
  .shell:not(.workspace-shell) .hero { margin-bottom: 32px; }
  .shell:not(.workspace-shell) .hero h1 { font-size: 34px; margin: 16px 0; }
  .shell:not(.workspace-shell) .hero .brand-logo { width: 56px; height: 56px; margin-bottom: 20px; }
  .shell:not(.workspace-shell) > .card { padding: 24px; }
}

/* Keep the login, signup, and password-reset forms in one consistent flow. */
.shell.auth-compact-shell{
  width:min(460px, calc(100% - 32px));
  min-height:100vh;
  margin:0 auto;
  padding:28px 0;
  display:grid;
  grid-template-columns:minmax(0,1fr);
  align-content:center;
  gap:0;
}
.shell.auth-compact-shell > .card{ width:100%; padding:clamp(24px, 6vw, 36px); }
.auth-compact-shell .auth-kicker{ margin-bottom:8px; }
.auth-compact-shell .card h1{ font-size:27px; line-height:1.4; }
.auth-compact-shell .auth-intro{ margin:10px 0 24px; }
.auth-compact-shell .auth-foot{ margin-top:22px; }

@media(max-width:600px){
  .legal{ width:calc(100% - 24px); margin:12px auto 28px; padding:22px 18px; border-radius:14px; }
  .legal-header .eyebrow{ margin-top:22px; }
  .legal-content{ margin-top:22px; }
  .legal-content section{ padding:18px 0; }
  .legal-content p{ font-size:14px; line-height:1.85; }
  .shell.auth-compact-shell{ width:calc(100% - 28px); padding:16px 0; }
  .shell.auth-compact-shell > .card{ padding:22px 18px; }
}