:root {
  --blue: #3182f6;
  --blue-dark: #1b64da;
  --blue-bg: #eef4ff;

  --mint: #06c799;
  --mint-bg: #e4faf3;

  --violet: #8b5cf6;
  --violet-bg: #f2edfe;

  --ink: #191f28;
  --ink-2: #4e5968;
  --ink-3: #8b95a1;
  --ink-4: #b0b8c1;

  --bg: #ffffff;
  --gray-bg: #f9fafb;
  --gray-bg-strong: #f2f4f6;
  --line: #eef0f2;

  --green: #17c964;
  --red: #f04452;
  --red-bg: #fef1f1;

  --font: "Pretendard Variable", Pretendard, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  --font-num: "Pretendard Variable", Pretendard, ui-monospace, "SFMono-Regular", Menlo, monospace;

  --r-lg: 20px;
  --r-md: 16px;
  --r-sm: 12px;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }

body {
  min-height: 100vh;
  margin: 0;
  color: var(--ink);
  background: var(--bg);
  font-family: var(--font);
  -webkit-font-smoothing: antialiased;
  letter-spacing: -0.01em;
}

a { color: inherit; }
button { font-family: inherit; }
:focus-visible { outline: 2px solid var(--blue); outline-offset: 2px; }

@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
}

/* ---------- shell ---------- */
.shell { width: min(100% - 2rem, 480px); margin-inline: auto; }
@media (min-width: 900px) { .shell { width: min(100% - 4rem, 640px); } }

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--line);
}
.nav-shell {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 56px;
}
.brand {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-weight: 800;
  font-size: 1rem;
  text-decoration: none;
}
.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 26px;
  height: 26px;
  border-radius: 8px;
  background: var(--gray-bg-strong);
  color: #fff;
  font-size: 0.68rem;
  font-weight: 800;
  object-fit: cover;
}
.top-nav { display: none; gap: 0.25rem; }
.top-nav a {
  padding: 0.5rem 0.85rem;
  border-radius: 999px;
  color: var(--ink-2);
  font-size: 0.86rem;
  font-weight: 700;
  text-decoration: none;
}
.top-nav a:hover { background: var(--gray-bg); color: var(--ink); }
.top-nav a[aria-current="page"] { background: var(--blue-bg); color: var(--blue-dark); }

@media (min-width: 720px) {
  .top-nav { display: flex; }
}

/* ---------- page ---------- */
.page-shell { padding-block: 1.75rem 3rem; }
.page-heading { margin-bottom: 1.5rem; }
.eyebrow {
  display: inline-block;
  margin-bottom: 0.55rem;
  color: var(--blue);
  font-size: 0.8rem;
  font-weight: 800;
  letter-spacing: -0.005em;
}
.page-heading h1 {
  margin: 0 0 0.5rem;
  font-size: clamp(1.5rem, 5vw, 2rem);
  font-weight: 800;
  line-height: 1.32;
  letter-spacing: -0.02em;
}
.page-heading p { margin: 0; color: var(--ink-2); line-height: 1.6; font-size: 0.94rem; }

/* ---------- menu card (home) ---------- */
.menu-card {
  border-radius: var(--r-lg);
  background: var(--gray-bg);
  overflow: hidden;
}
.menu-row {
  display: flex;
  align-items: center;
  gap: 0.9rem;
  padding: 1.05rem 1.15rem;
  text-decoration: none;
  color: var(--ink);
  border-bottom: 1px solid var(--line);
  transition: background 120ms ease;
}
.menu-row:last-child { border-bottom: 0; }
.menu-row:hover { background: var(--gray-bg-strong); }
.menu-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex: none;
  width: 44px;
  height: 44px;
  border-radius: 14px;
  background: var(--blue-bg);
  color: var(--blue-dark);
}
.menu-icon svg { width: 22px; height: 22px; }
.menu-icon--mint { background: var(--mint-bg); color: #04946f; }
.menu-icon--violet { background: var(--violet-bg); color: #6d3ff0; }
.menu-text { flex: 1; min-width: 0; }
.menu-text strong { display: block; font-size: 0.98rem; font-weight: 700; letter-spacing: -0.01em; }
.menu-text span { display: block; margin-top: 0.15rem; color: var(--ink-3); font-size: 0.82rem; line-height: 1.5; }
.menu-chevron { flex: none; color: var(--ink-4); }

section + section { margin-top: 1rem; }

/* ---------- status card ---------- */
.status-card {
  padding: 1.2rem 1.15rem 0.5rem;
  border-radius: var(--r-lg);
  background: var(--bg);
  border: 1px solid var(--line);
  box-shadow: 0 1px 2px rgba(15, 23, 42, 0.04), 0 10px 24px rgba(15, 23, 42, 0.05);
}
.status-head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-bottom: 0.9rem;
}
.status-title { font-size: 0.92rem; font-weight: 800; }
.status-title small { display: block; margin-top: 0.15rem; color: var(--ink-3); font-size: 0.76rem; font-weight: 500; }

/* countdown ring with the seconds-left number centered inside it */
.ring { position: relative; width: 44px; height: 44px; flex: none; }
.ring svg { width: 100%; height: 100%; transform: rotate(-90deg); overflow: visible; }
.ring circle { fill: none; stroke-width: 3.5; }
.ring .ring-track { stroke: var(--gray-bg-strong); }
.ring .ring-progress { stroke: var(--blue); stroke-linecap: round; }
.ring-count {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-num);
  font-size: 0.78rem;
  font-weight: 800;
  color: var(--ink-2);
  font-variant-numeric: tabular-nums;
}
@keyframes ring-pulse {
  0% { transform: scale(1); }
  35% { transform: scale(1.14); }
  100% { transform: scale(1); }
}
.ring.pulse { animation: ring-pulse 340ms cubic-bezier(0.34, 1.56, 0.64, 1); }
.ring.pulse .ring-progress { stroke: var(--mint); }

.status-list { display: grid; }
.status-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.85rem 0;
  border-top: 1px solid var(--line);
}
.status-item:first-child { border-top: 0; }
.status-name { font-size: 0.88rem; font-weight: 700; }
.status-right { display: flex; align-items: center; gap: 0.5rem; }
.status-meta { color: var(--ink-3); font-size: 0.8rem; font-family: var(--font-num); font-variant-numeric: tabular-nums; }

.status-pill {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  padding: 0.28rem 0.6rem;
  border-radius: 999px;
  background: var(--red-bg);
  color: var(--red);
  font-size: 0.74rem;
  font-weight: 700;
  white-space: nowrap;
}
.status-pill.online { background: var(--mint-bg); color: #04946f; }
.pill-dot { position: relative; width: 6px; height: 6px; border-radius: 999px; background: currentColor; flex: none; }
.status-pill.online .pill-dot::after {
  content: "";
  position: absolute;
  inset: -3px;
  border-radius: 999px;
  background: currentColor;
  opacity: 0.45;
  animation: pill-ripple 1.8s ease-out infinite;
}
@keyframes pill-ripple {
  0% { transform: scale(0.6); opacity: 0.45; }
  100% { transform: scale(2.4); opacity: 0; }
}


/* ---------- form ---------- */
.form-card { padding: 1.35rem 1.15rem; border-radius: var(--r-lg); background: var(--gray-bg); }
.field-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 0.85rem; }
.field-full { grid-column: 1 / -1; }
.field label { display: block; margin-bottom: 0.4rem; font-size: 0.84rem; font-weight: 700; color: var(--ink-2); }
.field-optional {
  margin-left: 0.35rem;
  padding: 0.05rem 0.4rem;
  border-radius: 0.3rem;
  background: var(--gray-bg-strong);
  color: var(--ink-3);
  font-size: 0.68rem;
  font-weight: 700;
}
.field input {
  width: 100%;
  min-height: 52px;
  padding: 0.8rem 1rem;
  border: 1.5px solid transparent;
  border-radius: var(--r-md);
  outline: 0;
  background: var(--bg);
  color: var(--ink);
  font-size: 0.98rem;
  font-family: var(--font);
  transition: border-color 120ms ease, box-shadow 120ms ease;
}
.field input::placeholder { color: var(--ink-4); }
.field input:focus { border-color: var(--blue); box-shadow: 0 0 0 4px var(--blue-bg); }
.hint { margin-top: 0.4rem; color: var(--ink-3); font-size: 0.78rem; }

.button-row { margin-top: 1.25rem; }
.button {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.4rem;
  width: 100%;
  min-height: 56px;
  border: none;
  border-radius: var(--r-md);
  background: var(--blue);
  color: #fff;
  font-weight: 800;
  font-size: 1rem;
  letter-spacing: -0.01em;
  cursor: pointer;
  transition: background 120ms ease, transform 120ms ease;
}
.button:hover { background: var(--blue-dark); }
.button:active { transform: scale(0.99); }
.button:disabled { opacity: 0.55; cursor: wait; }
.button-secondary { background: var(--bg); color: var(--ink); border: 1.5px solid var(--line); }
.button-secondary:hover { background: var(--gray-bg); }
.button-row.split { display: flex; gap: 0.6rem; }
.button-row.split .button { width: auto; flex: 1; }

.action-button { min-width: 0; }
.button-action-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 20px;
  height: 20px;
  flex: none;
}
.button-action-icon svg { width: 20px; height: 20px; }
.button.is-loading { opacity: 0.68; }
.button.is-success { background: var(--green); color: #fff; }
.button.button-secondary.is-success { border-color: transparent; }
.button.is-error { background: var(--red); color: #fff; }
.button.button-secondary.is-error { border-color: transparent; }
.button-spinner {
  width: 18px;
  height: 18px;
  border: 2px solid currentColor;
  border-right-color: transparent;
  border-radius: 999px;
  animation: button-spin 650ms linear infinite;
}
@keyframes button-spin { to { transform: rotate(360deg); } }



/* ---------- result ---------- */
.result { display: none; margin-top: 1rem; }
.result.visible { display: block; animation: rise 220ms ease; }
@keyframes rise { from { opacity: 0; transform: translateY(6px); } to { opacity: 1; transform: translateY(0); } }

.notice {
  padding: 1rem 1.1rem;
  border-radius: var(--r-md);
  background: var(--red-bg);
  color: var(--red);
  font-size: 0.9rem;
  font-weight: 700;
}

.url-action-notice { margin-top: 0.75rem; }

.result-card { padding: 1.25rem 1.15rem; border-radius: var(--r-lg); background: var(--gray-bg); }
.result-top { display: flex; justify-content: space-between; align-items: flex-start; gap: 1rem; margin-bottom: 1.1rem; }
.result-top h2 { margin: 0; font-size: 1.08rem; font-weight: 800; letter-spacing: -0.01em; }
.result-top p { margin: 0.25rem 0 0; color: var(--ink-3); font-size: 0.84rem; }
.result-side { text-align: right; }
.result-side strong { display: block; font-size: 0.94rem; font-weight: 800; }
.result-side span { display: block; margin-top: 0.1rem; color: var(--ink-3); font-size: 0.78rem; }

.data-list { border-radius: var(--r-md); background: var(--bg); overflow: hidden; }
.data-row { display: flex; justify-content: space-between; align-items: center; gap: 1rem; padding: 0.8rem 0.95rem; border-top: 1px solid var(--line); }
.data-row:first-child { border-top: 0; }
.id-tag { padding: 0.15rem 0.5rem; border-radius: 0.4rem; background: var(--gray-bg-strong); font-family: var(--font-num); font-size: 0.78rem; color: var(--ink-2); }
.data-value { font-weight: 700; text-align: right; }
.empty-note { padding: 1rem; text-align: center; color: var(--ink-3); font-size: 0.88rem; background: var(--bg); border-radius: var(--r-md); }

.course-list { background: var(--bg); border-radius: var(--r-md); overflow: hidden; }
.course-card { padding: 0.95rem; border-top: 1px solid var(--line); }
.course-card:first-child { border-top: 0; }
.course-card h3 { margin: 0 0 0.45rem; font-size: 0.94rem; font-weight: 700; }
.course-meta { display: flex; flex-wrap: wrap; gap: 0.35rem 0.8rem; }
.course-meta span { color: var(--ink-3); font-size: 0.78rem; font-family: var(--font-num); }

.url-output {
  padding: 1rem;
  border-radius: var(--r-md);
  background: var(--bg);
  overflow-wrap: anywhere;
  font-family: var(--font-num);
  font-size: 0.85rem;
  color: var(--ink-2);
}

/* ---------- footer ---------- */
.site-footer {
  padding: 1.5rem 1rem calc(6.5rem);
  color: var(--ink-3);
  text-align: center;
  font-size: 0.78rem;
}
.site-footer a { color: var(--ink-2); font-weight: 700; text-decoration: none; }
.site-footer a:hover { color: var(--blue); text-decoration: underline; }

@media (min-width: 720px) {
  .site-footer { padding: 1.5rem 1rem 2.5rem; }
}

/* ---------- bottom tab bar (mobile) ---------- */
.tab-bar {
  position: fixed;
  left: 0; right: 0; bottom: 0;
  z-index: 30;
  display: flex;
  border-top: 1px solid var(--line);
  background: rgba(255, 255, 255, 0.96);
  backdrop-filter: blur(10px);
  padding-bottom: env(safe-area-inset-bottom);
}
.tab-bar a {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.25rem;
  padding: 0.55rem 0 0.6rem;
  color: var(--ink-4);
  text-decoration: none;
  font-size: 0.68rem;
  font-weight: 700;
}
.tab-bar a svg { width: 22px; height: 22px; }
.tab-bar a[aria-current="page"] { color: var(--blue); }
.page-shell { padding-bottom: 5.5rem; }

@media (min-width: 720px) {
  .tab-bar { display: none; }
  .page-shell { padding-bottom: 3rem; }
}

@media (max-width: 480px) {
  .field-grid { grid-template-columns: 1fr; }
  .field-full { grid-column: auto; }
  .result-top { flex-direction: column; }
  .result-side { text-align: left; }
}