:root {
  --ink: #14213D; --muted: #5B6478; --line: #E3E6EE; --soft: #F6F7FB; --blue: #2448C9; --blue-dk: #1A3599;
  --blue-soft: #EAF0FF; --orange: #E26A2C; --orange-dk: #B4410C; --orange-soft: #FFF6EC; --green: #15803D;
  --green-soft: #E8F6EC; --radius: 16px;
}
* { box-sizing: border-box; }
[hidden] { display: none !important; }
html, body { margin: 0; }
body { font-family: 'Plus Jakarta Sans', system-ui, sans-serif; color: var(--ink); background: var(--soft); min-height: 100vh; display: flex; flex-direction: column; }
a { color: var(--blue); } a:hover { color: var(--blue-dk); }
.wrap { width: 100%; max-width: 1100px; margin: 0 auto; padding: 0 20px; }
main.wrap { flex: 1; padding-top: 28px; padding-bottom: 48px; outline: none; }
h1 { font-size: 28px; letter-spacing: -0.4px; margin: 0 0 6px; }
h2 { font-size: 18px; margin: 0 0 10px; }
p { line-height: 1.5; }
.muted { color: var(--muted); } .small { font-size: 13.5px; }
.topbar { background: #fff; border-bottom: 1px solid var(--line); }
.topbar-inner { display: flex; align-items: center; justify-content: space-between; gap: 12px; padding-top: 12px; padding-bottom: 12px; flex-wrap: wrap; }
.brand { display: flex; align-items: center; gap: 10px; font-size: 18px; font-weight: 800; color: var(--ink); text-decoration: none; }
.topbar-right { display: flex; align-items: center; gap: 12px; flex-wrap: wrap; }
.lang { display: flex; background: #F1F3F8; border-radius: 999px; padding: 3px; }
.lang button { border: 0; background: transparent; color: var(--muted); font-family: inherit; font-weight: 600; font-size: 13px; padding: 0 14px; height: 38px; border-radius: 999px; cursor: pointer; }
.lang button[aria-pressed="true"] { background: #fff; color: var(--ink); font-weight: 800; box-shadow: 0 1px 2px rgba(20,33,61,.12); }
.footer { border-top: 1px solid var(--line); background: #fff; padding: 16px 0; }
.card { background: #fff; border: 1px solid var(--line); border-radius: 20px; padding: 24px; }
.grid { display: grid; gap: 16px; }
.cols-auto { grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); }
.row { display: flex; gap: 12px; flex-wrap: wrap; align-items: center; }
.stack { display: flex; flex-direction: column; gap: 14px; }
.split { display: flex; flex-wrap: wrap; gap: 24px; align-items: flex-start; }
.split > .main { flex: 999 1 520px; min-width: 0; }
.split > .side { flex: 1 1 300px; min-width: 0; }
.btn { display: inline-flex; align-items: center; justify-content: center; gap: 8px; min-height: 48px; padding: 0 20px; border-radius: 12px; border: 0; background: var(--blue); color: #fff; font-family: inherit; font-weight: 700; font-size: 15px; cursor: pointer; text-decoration: none; }
.btn:hover { background: var(--blue-dk); color: #fff; }
.btn[disabled] { opacity: .55; cursor: not-allowed; }
.btn-ghost { background: #fff; color: var(--ink); border: 1.5px solid #CBD2E0; }
.btn-ghost:hover { background: var(--soft); color: var(--ink); }
.btn-sm { min-height: 40px; padding: 0 14px; font-size: 13.5px; }
.btn-lg { min-height: 56px; font-size: 17px; padding: 0 26px; }
label.field { display: flex; flex-direction: column; gap: 6px; font-size: 14px; font-weight: 700; }
input, select { height: 48px; border: 1.5px solid #CBD2E0; border-radius: 12px; padding: 0 14px; font-family: inherit; font-weight: 600; font-size: 16px; color: var(--ink); background: #fff; min-width: 0; }
input:focus, select:focus, button:focus-visible, a:focus-visible { outline: 3px solid #8FA8FF; outline-offset: 2px; }
.check { display: flex; gap: 12px; align-items: flex-start; font-size: 14px; line-height: 1.5; color: #3A4560; font-weight: 500; }
.check input { width: 22px; height: 22px; margin: 0; flex-shrink: 0; accent-color: var(--blue); }
.pills { display: flex; gap: 8px; }
.pill { flex: 1; min-height: 48px; border: 1.5px solid #CBD2E0; border-radius: 12px; background: #fff; color: var(--ink); font-family: inherit; font-weight: 600; font-size: 15px; cursor: pointer; }
.pill[aria-pressed="true"] { background: var(--blue); color: #fff; border-color: var(--blue); font-weight: 800; }
.error { background: #FDECEC; color: #9B1C1C; border-radius: 12px; padding: 10px 14px; font-size: 14px; }
.note { background: var(--blue-soft); color: var(--blue-dk); border-radius: 12px; padding: 12px 14px; font-size: 14px; }
.warm { background: var(--orange-soft); color: #7A2E08; border-radius: 16px; padding: 16px 18px; }
.badge { display: inline-block; font-size: 12.5px; font-weight: 800; padding: 5px 10px; border-radius: 999px; }
.badge-green { background: var(--green-soft); color: var(--green); }
.badge-blue { background: var(--blue-soft); color: var(--blue-dk); }
.badge-orange { background: #FFF1E6; color: var(--orange-dk); }
.stat { background: #fff; border: 1px solid var(--line); border-radius: 16px; padding: 16px; display: flex; flex-direction: column; gap: 4px; }
.stat b { font-size: 26px; }
.bar { height: 10px; background: #EEF0F5; border-radius: 999px; overflow: hidden; }
.bar > span { display: block; height: 100%; border-radius: 999px; background: var(--blue); }
.bar.orange > span { background: var(--orange); } .bar.green > span { background: #2E9E5B; }
.session { display: flex; gap: 14px; align-items: center; background: #fff; border: 1px solid var(--line); border-radius: 16px; padding: 14px 16px; }
.session.next { border: 2px solid var(--blue); }
.session .ico { width: 44px; height: 44px; border-radius: 12px; background: var(--blue-soft); display: flex; align-items: center; justify-content: center; flex-shrink: 0; font-weight: 800; color: var(--blue-dk); }
.session.done .ico { background: var(--green-soft); color: var(--green); }
.session .grow { flex: 1; display: flex; flex-direction: column; gap: 2px; }
.kicker { font-size: 12.5px; font-weight: 800; text-transform: uppercase; letter-spacing: .6px; color: var(--blue-dk); }
.question { font-size: 23px; font-weight: 700; line-height: 1.35; margin: 4px 0 6px; }
.choices { display: flex; flex-direction: column; gap: 10px; }
.choice { display: flex; align-items: center; gap: 14px; min-height: 56px; padding: 8px 16px; border-radius: 14px; background: #fff; border: 1.5px solid #CBD2E0; text-align: left; font-family: inherit; font-weight: 600; font-size: 17px; color: var(--ink); cursor: pointer; }
.choice .letter { width: 32px; height: 32px; border-radius: 999px; display: flex; align-items: center; justify-content: center; font-size: 14px; font-weight: 800; background: #F1F3F8; color: #3A4560; flex-shrink: 0; }
.choice[aria-checked="true"] { background: var(--blue-soft); border: 2px solid var(--blue); }
.choice[aria-checked="true"] .letter { background: var(--blue); color: #fff; }
.choice.right { background: var(--green-soft); border: 2px solid #2E9E5B; }
.choice.right .letter { background: var(--green); color: #fff; }
.choice.wrong { background: var(--orange-soft); border: 2px solid var(--orange); }
.choice.wrong .letter { background: var(--orange-dk); color: #fff; }
.choice[disabled] { cursor: default; }
.passage { background: #fff; border: 1px solid var(--line); border-radius: 16px; padding: 18px 20px; font-size: 15.5px; line-height: 1.65; max-height: 420px; overflow: auto; white-space: pre-wrap; }
.progress { height: 8px; background: #EEF0F5; border-radius: 999px; overflow: hidden; }
.progress > span { display: block; height: 100%; background: var(--blue); }
.chat { display: flex; flex-direction: column; border: 1px solid var(--line); border-radius: 20px; background: #fff; overflow: hidden; }
.chat-head { padding: 14px 18px; border-bottom: 1px solid #EEF0F5; display: flex; gap: 10px; align-items: center; }
.chat-body { padding: 16px 18px; display: flex; flex-direction: column; gap: 10px; min-height: 160px; max-height: 420px; overflow: auto; }
.msg { max-width: 85%; padding: 10px 14px; font-size: 14.5px; line-height: 1.5; white-space: pre-wrap; }
.msg.user { align-self: flex-end; background: var(--blue); color: #fff; border-radius: 16px 16px 4px 16px; }
.msg.assistant { align-self: flex-start; background: #F1F3F8; border-radius: 16px 16px 16px 4px; }
.msg.flag { outline: 2px solid var(--orange); }
.chat form { display: flex; gap: 10px; padding: 12px 14px; border-top: 1px solid #EEF0F5; }
.chat form input { flex: 1; }
.sr-only { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; }
table { width: 100%; border-collapse: collapse; font-size: 14px; }
th, td { text-align: left; padding: 10px 8px; border-bottom: 1px solid #EEF0F5; }
th { font-size: 12.5px; color: var(--muted); text-transform: uppercase; letter-spacing: .5px; }
@media (max-width: 600px) { h1 { font-size: 24px; } .question { font-size: 20px; } .card { padding: 18px; } }

/* ---------- color: one accent per SSAT section, brighter page ---------- */
.sec-verbal { --accent: #7C3AED; --accent-soft: #F1EAFE; }
.sec-quant { --accent: #0D9488; --accent-soft: #E0F5F2; }
.sec-reading { --accent: #C2185B; --accent-soft: #FCE7F0; }
body { background: linear-gradient(180deg, #EDF1FF 0, #F6F7FB 360px) no-repeat, var(--soft); }
.topbar { border-bottom: 0; }
.topbar::after { content: ""; display: block; height: 4px; background: linear-gradient(90deg, #2448C9, #7C3AED, #C2185B, #E26A2C, #0D9488); }
.footer { border-top: 0; background: #fff; box-shadow: 0 -1px 0 var(--line); }
.session[class*="sec-"] { border-left: 6px solid var(--accent); }
.session[class*="sec-"] .ico { background: var(--accent-soft); color: var(--accent); font-size: 20px; }
.session[class*="sec-"].done .ico { background: var(--green-soft); color: var(--green); }
.session.next[class*="sec-"] { border-left-width: 6px; box-shadow: 0 6px 18px rgba(36,72,201,.12); }
.kicker[class*="sec-"], .sec-title { color: var(--accent); }
.progress[class*="sec-"] > span { background: linear-gradient(90deg, var(--accent), #2448C9); }
.btn-sec { background: var(--accent-soft); color: var(--accent); border: 1.5px solid transparent; justify-content: flex-start; }
.btn-sec:hover { background: var(--accent); color: #fff; }
.card { box-shadow: 0 2px 10px rgba(20,33,61,.05); }
.badge-orange { background: linear-gradient(90deg, #FFE7D3, #FFF1E6); }
.choice:hover:not([disabled]) { border-color: #8FA8FF; }
.note { border-left: 4px solid var(--blue); }
.warm { border-left: 4px solid var(--orange); }
.msg.assistant { background: #EEF1FF; }
.session[class*="sec-"] .kicker { color: var(--accent); }
.sketch-wrap { background: #fff; border: 1px solid var(--line); border-radius: 12px; padding: 8px; margin: 8px 0; white-space: normal; }
.sketch { display: block; max-width: 100%; height: auto; }
.msg:has(.sketch-wrap) { max-width: 95%; }