/* Blue palette after topikguide.com: #1887e5 brand, deep navy ink. */
:root {
  --bg: #f7f9fc;
  --card: #ffffff;
  --ink: #142433;
  --muted: #5b6b7c;
  --line: #e2e8f0;
  --brand: #1887e5;
  --brand-deep: #0f5fa6;      /* text on light backgrounds (links, outline buttons) */
  --brand-ink: #ffffff;
  --brand-soft: #eaf4fd;
  --ok: #138a4f;
  --ok-soft: #e4f6ec;
  --bad: #c22a2f;
  --bad-soft: #fde9e7;
  --warn: #b26a00;
  --radius: 14px;
  --shadow: 0 1px 2px rgba(20, 36, 51, .05);
  --kr: 'Inter', 'Noto Sans KR', 'Apple SD Gothic Neo', 'Malgun Gothic', sans-serif;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0d1620; --card: #142231; --ink: #e6edf5; --muted: #98a8ba; --line: #24364a;
    --brand: #3b9ff0; --brand-deep: #8cc6f7; --brand-ink: #ffffff; --brand-soft: #16304a;
    --ok: #4cc98a; --ok-soft: #133524; --bad: #f26d70; --bad-soft: #3a1a1a; --warn: #f0b04a;
    --shadow: 0 1px 2px rgba(0, 0, 0, .3);
  }
}

* { box-sizing: border-box; }
body { margin: 0; background: var(--bg); color: var(--ink); font: 16px/1.6 var(--kr); }
a { color: var(--brand-deep); }
img { max-width: 100%; height: auto; }
.container { max-width: 860px; margin: 0 auto; padding: calc(var(--nav-space) + 8px) 16px 96px; }
.muted { color: var(--muted); }
.small { font-size: 14px; }

/* Floating glass navigation (like zushop.mn): a pill that hovers over the page, frosted with blur.
   It is fixed, so pages reserve --nav-space at the top (the home hero runs underneath it). */
:root { --nav-space: 84px; }
.topbar { position: fixed; top: 12px; left: 50%; transform: translateX(-50%); z-index: 30;
  width: min(1100px, calc(100% - 24px)); display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; gap: 12px;
  padding: 8px 8px 8px 16px; border-radius: 999px;
  background: color-mix(in srgb, var(--card) 62%, transparent);
  -webkit-backdrop-filter: saturate(180%) blur(20px); backdrop-filter: saturate(180%) blur(20px);
  border: 1px solid color-mix(in srgb, #ffffff 55%, transparent);
  box-shadow: 0 8px 32px rgba(20, 36, 51, .12), inset 0 1px 0 rgba(255, 255, 255, .5); }
@media (prefers-color-scheme: dark) {
  .topbar { border-color: rgba(255, 255, 255, .1); box-shadow: 0 8px 32px rgba(0, 0, 0, .4), inset 0 1px 0 rgba(255, 255, 255, .06); }
}
.brand { justify-self: start; font-weight: 800; text-decoration: none; color: var(--ink); font-size: 17px; display: inline-flex; align-items: center; gap: 8px; }
.brand .logo { display: grid; place-items: center; width: 30px; height: 30px; border-radius: 9px; color: #fff; font-size: 15px; background: var(--brand); }
.brand span { color: var(--brand-deep); }
.topbar nav { display: flex; gap: 2px; align-items: center; }
.brand, .topbar nav a { white-space: nowrap; }
.topbar nav a { text-decoration: none; color: var(--muted); font-weight: 500; font-size: 15px; padding: 7px 13px; border-radius: 999px;
  transition: color .15s, background .15s; }
.topbar nav a:hover { color: var(--ink); background: color-mix(in srgb, var(--ink) 6%, transparent); }
.topbar nav a.on { color: var(--ink); background: color-mix(in srgb, var(--card) 85%, transparent); box-shadow: 0 1px 4px rgba(20, 36, 51, .1); }
.nav-right { justify-self: end; display: flex; align-items: center; gap: 6px; }
.menu-btn { display: none; width: 40px; height: 40px; border: 0; border-radius: 50%; cursor: pointer; padding: 0;
  background: color-mix(in srgb, var(--ink) 6%, transparent); place-content: center; gap: 4px; }
.menu-btn span { display: block; width: 18px; height: 2px; border-radius: 2px; background: var(--ink); transition: transform .2s, opacity .2s; }
.topbar.open .menu-btn span:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.topbar.open .menu-btn span:nth-child(2) { opacity: 0; }
.topbar.open .menu-btn span:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }
.nav-auth { display: inline-flex; align-items: center; gap: 7px; white-space: nowrap; text-decoration: none;
  padding: 8px 16px 8px 12px; border-radius: 999px; font: 600 14px var(--kr); color: var(--ink);
  background: color-mix(in srgb, var(--card) 70%, transparent); border: 1px solid color-mix(in srgb, var(--ink) 12%, transparent);
  transition: background .15s, border-color .15s; }
.nav-auth svg { color: var(--brand-deep); }
.nav-auth:hover { background: var(--card); border-color: color-mix(in srgb, var(--brand) 45%, transparent); }
/* signed in: just a round avatar with the e-mail's first letter */
.nav-auth.avatar { width: 38px; height: 38px; padding: 0; justify-content: center; color: #fff; font-size: 16px;
  background: var(--brand); border-color: transparent; box-shadow: 0 0 0 3px color-mix(in srgb, var(--brand) 20%, transparent); }

h1 { font-size: 24px; line-height: 1.3; margin: 8px 0; }
h2 { font-size: 19px; margin: 0 0 8px; }
.hero p { color: var(--muted); }

.card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 16px; box-shadow: var(--shadow); }
.card.error { border-color: var(--bad); }

.btn { display: inline-block; border: 0; border-radius: 8px; padding: 10px 18px; background: var(--brand);
  color: var(--brand-ink); font: 600 15px var(--kr); text-decoration: none; cursor: pointer; }
.btn.small { padding: 6px 12px; font-size: 14px; }
.btn.ghost { background: var(--brand-soft); color: var(--brand-deep); }
.btn:disabled { opacity: .5; cursor: default; }

/* home */
.test-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 12px; margin-top: 16px; }
.test-card .row { display: flex; justify-content: space-between; align-items: center; gap: 8px;
  padding: 8px 0; border-top: 1px solid var(--line); }
.test-card .btns { display: flex; gap: 6px; }

/* practice builder */
.pr-head h1 { margin-bottom: 4px; }
.pr-head p { margin: 0 0 18px; }
.pr-step { margin-bottom: 26px; }
.pr-step h2 { display: flex; align-items: center; gap: 10px; font-size: 17px; margin: 0 0 12px; }
.pr-step h2 .num { display: grid; place-items: center; width: 26px; height: 26px; border-radius: 50%; font-size: 13px; color: #fff; background: var(--brand); }
.link-btn { margin-left: auto; border: 0; background: none; color: var(--brand-deep); font: 600 14px var(--kr); cursor: pointer; }
.pr-sections, .pr-modes { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.pr-opt { display: grid; gap: 2px; justify-items: start; text-align: left; padding: 14px 16px; border-radius: 14px; cursor: pointer;
  border: 1.5px solid var(--line); background: var(--card); color: var(--ink); font: inherit; transition: border-color .15s, background .15s; }
.pr-opt .ico { font-size: 22px; margin-bottom: 4px; }
.pr-opt b { font-size: 16px; }
.pr-opt small { color: var(--muted); font-size: 13px; }
.pr-opt:hover { border-color: color-mix(in srgb, var(--brand) 50%, var(--line)); }
.pr-opt.on { border-color: var(--brand); background: var(--brand-soft); box-shadow: 0 0 0 3px color-mix(in srgb, var(--brand) 18%, transparent); }
.pr-ranges { display: grid; grid-template-columns: repeat(auto-fill, minmax(170px, 1fr)); gap: 8px; }
.pr-range { display: grid; gap: 2px; justify-items: start; text-align: left; padding: 10px 12px; border-radius: 12px; cursor: pointer;
  border: 1.5px solid var(--line); background: var(--card); color: var(--ink); font: inherit; transition: border-color .15s, background .15s; }
.pr-range b { font-size: 18px; color: var(--brand-deep); }
.pr-range span { font-size: 13px; color: var(--muted); line-height: 1.35; }
.pr-range:hover { border-color: color-mix(in srgb, var(--brand) 50%, var(--line)); }
.pr-range.on { border-color: var(--brand); background: var(--brand); }
.pr-range.on b, .pr-range.on span { color: #fff; }
.pr-custom { margin-top: 12px; display: flex; flex-wrap: wrap; align-items: center; gap: 6px; font-size: 15px; }
.pr-custom input { width: 64px; padding: 7px; border: 1px solid var(--line); border-radius: 8px; background: var(--card); color: var(--ink); font: inherit; }
.pr-rounds { display: flex; flex-wrap: wrap; gap: 8px; }
.pr-round { min-width: 58px; padding: 8px 12px; border-radius: 10px; cursor: pointer; font: 700 15px var(--kr);
  border: 1.5px solid var(--line); background: var(--card); color: var(--muted); }
.pr-round small { font-weight: 500; margin-left: 1px; }
.pr-round.on { border-color: var(--brand); background: var(--brand-soft); color: var(--brand-deep); }
.pr-bar { position: sticky; bottom: 12px; z-index: 5; display: flex; align-items: center; justify-content: space-between; gap: 12px;
  padding: 12px 12px 12px 18px; border-radius: 16px; margin-top: 8px;
  background: color-mix(in srgb, var(--card) 85%, transparent); -webkit-backdrop-filter: blur(16px); backdrop-filter: blur(16px);
  border: 1px solid var(--line); box-shadow: 0 10px 30px rgba(20, 36, 51, .12); }
.pr-summary { display: grid; line-height: 1.3; min-width: 0; }
.pr-summary span { color: var(--muted); font-size: 14px; }
.pr-bar .btn { flex: none; padding: 12px 22px; }
.bad-text { color: var(--bad); }

/* session */
.session-head { margin-bottom: 12px; }
.autoplay { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; font-size: 14px; }
.autoplay audio { height: 36px; }
.full-player { position: sticky; top: var(--nav-space); z-index: 4; background: var(--bg); padding: 8px 0 4px; }
.full-player audio { width: 100%; }
.full-player p { margin: 2px 0 0; }
.block.playing { border-color: var(--brand-deep); box-shadow: 0 0 0 2px var(--brand-soft); }
.seek { margin-left: auto; border: 0; background: none; color: var(--brand-deep); font: 13px var(--kr); cursor: pointer; }
#blocks { display: flex; flex-direction: column; gap: 14px; }
.block { scroll-margin-top: calc(var(--nav-space) + 80px); }
.block-head { display: flex; gap: 8px; align-items: center; color: var(--muted); font-size: 14px; margin-bottom: 6px; }
.tag { background: var(--brand-soft); color: var(--brand-deep); border-radius: 6px; padding: 1px 8px; font-weight: 700; }
.instruction { font-weight: 700; margin: 0 0 10px; }
.stimulus { margin-bottom: 12px; }
.stimulus audio { width: 100%; margin-bottom: 6px; }
.passage { border: 1px solid var(--line); border-radius: 8px; padding: 12px 14px; line-height: 1.9; white-space: pre-line; }
.passage.sentences p { margin: 2px 0; }
.insert { border: 1px dashed var(--muted); border-radius: 8px; padding: 10px 14px; margin-bottom: 10px; }
.insert .label { font-weight: 700; margin-right: 6px; }
.notice { font-size: 14px; color: var(--warn); border-left: 3px solid var(--warn); padding: 4px 10px; margin: 0 0 10px; }
.figure { display: block; margin: 0 auto 10px; border-radius: 6px; background: #fff; }
u { text-decoration-thickness: 1.5px; text-underline-offset: 3px; }

.transcript { background: var(--brand-soft); border-radius: 8px; padding: 10px 14px; margin-top: 6px; }
.transcript summary { cursor: pointer; font-weight: 700; color: var(--brand-deep); }
.transcript p { margin: 6px 0; }
.speaker { color: var(--brand-deep); }

.question { margin-top: 12px; }
.prompt { margin: 0 0 8px; }
.choices { list-style: none; padding: 0; margin: 0; display: grid; gap: 6px; }
.choices.images { grid-template-columns: repeat(2, 1fr); }
.choice { width: 100%; display: flex; gap: 10px; align-items: flex-start; text-align: left; padding: 8px 12px;
  border: 1px solid var(--line); border-radius: 8px; background: var(--card); color: var(--ink); font: inherit; cursor: pointer; }
.choices.images .choice { flex-direction: column; align-items: center; }
.choices.images img { background: #fff; border-radius: 4px; }
.choice:hover:not(:disabled) { border-color: var(--brand-deep); }
.choice .num { font-weight: 700; color: var(--muted); }
.choice.picked { border-color: var(--brand-deep); background: var(--brand-soft); }
.choice.correct { border-color: var(--ok); background: var(--ok-soft); }
.choice.wrong { border-color: var(--bad); background: var(--bad-soft); }
.choice:disabled { cursor: default; }

.statusbar { position: fixed; left: 0; right: 0; bottom: 0; display: flex; justify-content: center; align-items: center;
  gap: 16px; padding: 10px 16px; background: var(--card); border-top: 1px solid var(--line); z-index: 5; font-size: 15px; }
#timer { font-variant-numeric: tabular-nums; font-weight: 700; }
#timer.low { color: var(--bad); }
.result { margin-bottom: 14px; border-color: var(--brand-deep); }

/* writing */
.answer { position: relative; margin-top: 10px; }
.answer .blank { font-weight: 700; display: block; }
.answer textarea { width: 100%; padding: 10px; border: 1px solid var(--line); border-radius: 8px;
  background: var(--card); color: var(--ink); font: 16px/1.8 var(--kr); resize: vertical; }
.answer .count { display: block; text-align: right; color: var(--muted); font-size: 13px; }
.answer .count.warn { color: var(--warn); }
.model { margin-top: 10px; }
.model summary { cursor: pointer; font-weight: 700; color: var(--brand-deep); }
.model .essay, .model .notes { white-space: normal; line-height: 1.9; margin-top: 8px; }

@media (max-width: 560px) {
  :root { --nav-space: 76px; }
  h1 { font-size: 21px; }
  /* hamburger: links drop down as a frosted panel under the pill */
  .topbar { grid-template-columns: 1fr auto; padding: 6px 6px 6px 12px; }
  .menu-btn { display: grid; }
  .topbar nav { display: none; position: absolute; top: calc(100% + 8px); left: 0; right: 0; flex-direction: column; align-items: stretch;
    gap: 2px; padding: 8px; border-radius: 20px; background: var(--card); /* opaque: nested blur doesn't work in Chrome */
    border: 1px solid color-mix(in srgb, var(--ink) 8%, transparent); box-shadow: 0 16px 40px rgba(20, 36, 51, .18); }
  .topbar.open nav { display: flex; }
  .topbar nav a { font-size: 16px; padding: 12px 14px; border-radius: 12px; }
  .brand { font-size: 16px; }
  .brand .logo { width: 28px; height: 28px; }
  .nav-auth { padding: 8px 12px 8px 10px; }
  .brand-sub { display: none; }
  .choices.images { grid-template-columns: 1fr 1fr; }
  .statusbar { gap: 10px; font-size: 14px; }
}

/* login / account */
.auth-wrap { display: grid; place-items: start center; padding-top: 24px; }
.auth-card { width: min(420px, 100%); padding: 28px; border-radius: 18px; }
.auth-card h1 { margin: 0 0 4px; }
.auth-card > p { margin: 0 0 18px; }
.btn.google { width: 100%; display: flex; justify-content: center; align-items: center; gap: 10px; padding: 12px;
  background: var(--card); color: var(--ink); border: 1px solid var(--line); }
.btn.google:hover { background: var(--brand-soft); }
.or { display: flex; align-items: center; gap: 10px; margin: 18px 0; color: var(--muted); font-size: 13px; }
.or::before, .or::after { content: ''; flex: 1; height: 1px; background: var(--line); }
#email-form { display: grid; gap: 8px; }
#email-form input { padding: 11px 12px; border: 1px solid var(--line); border-radius: 10px; background: var(--card); color: var(--ink); font: 16px var(--kr); }
#email-form input:focus { outline: 2px solid color-mix(in srgb, var(--brand) 50%, transparent); outline-offset: 1px; }
#email-form .btn { padding: 12px; }
.auth-msg { margin: 14px 0 0; font-size: 14px; }
.auth-msg.ok { color: var(--ok); }
.auth-msg.bad { color: var(--bad); }
.plan { display: grid; gap: 4px; padding: 14px; border-radius: 12px; margin: 14px 0 18px; background: var(--brand-soft); }
.plan span { color: var(--muted); font-size: 14px; }
.plan.on { background: var(--ok-soft); }
.plan.on b { color: var(--ok); }
.btn.line-dark { background: transparent; color: var(--muted); border: 1px solid var(--line); }