/* LectureRoom landing page: two big choices, nothing else */
:root { --bg:#0d1f18; --panel:#142c23; --line:#2a4a3d; --ink:#eef5f1; --mute:#a9c2b7; --acc:#f2b544; --accink:#1b1405; }
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body.lp { margin: 0; min-height: 100vh; min-height: 100dvh; display: flex; flex-direction: column; background: var(--bg); color: var(--ink);
  font: 17px/1.5 system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif; }
.lp a { color: var(--acc); }
.lp-top { display: flex; align-items: center; justify-content: space-between; padding: 14px 20px; max-width: 980px; width: 100%; margin: 0 auto; }
.lp-brand { display: inline-flex; align-items: center; gap: 10px; color: var(--ink) !important; text-decoration: none; font-weight: 700; font-size: 19px; }
.lp-brand .mark { width: 34px; height: 34px; display: grid; place-items: center; border-radius: 10px; background: var(--acc); color: var(--accink); }
.lp-top nav a { color: var(--mute); text-decoration: none; font-size: 15px; padding: 8px; }
.lp-main { flex: 1; width: 100%; max-width: 980px; margin: 0 auto; padding: 14px 20px 28px; }
.lp h1 { margin: 6px 0 4px; font-size: clamp(28px, 6vw, 40px); line-height: 1.15; letter-spacing: -.01em; }
.lp-sub { margin: 0 0 22px; color: var(--mute); font-size: 18px; }
.lp .notice { background: #3a2f12; border: 1px solid #7a6220; color: #ffe9b0; padding: 12px 14px; border-radius: 12px; margin: 0 0 18px; font-size: 15px; }

.lp-cards { display: grid; grid-template-columns: 1.1fr 1fr; gap: 16px; align-items: stretch; }
@media (max-width: 760px) { .lp-cards { grid-template-columns: 1fr; } }
.lp-card { display: flex; flex-direction: column; gap: 12px; padding: 22px; border-radius: 20px; background: var(--panel); border: 1px solid var(--line); margin: 0; }
.lp-teach { border-color: #5b4a1c; background: linear-gradient(180deg, #1a2f26, var(--panel)); }
.lp-step { align-self: flex-start; font-size: 13px; font-weight: 600; letter-spacing: .04em; text-transform: uppercase; color: var(--mute); }
.lp-card h2 { margin: 0; font-size: 26px; line-height: 1.2; }
.lp-card h2 label { cursor: pointer; }
.lp input[type=text], .lp input:not([type]), .lp select { width: 100%; height: 54px; padding: 0 14px; border-radius: 14px; border: 2px solid #3a6050; background: #0d1f18; color: var(--ink); font-family: system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif; font-size: 18px; }
.lp select { font-size: 16px; }
.lp input::placeholder { color: #7f9a8f; }
.lp input:focus, .lp select:focus, .lp summary:focus-visible { outline: 3px solid var(--acc); outline-offset: 2px; border-color: var(--acc); }
.lp-btn { display: inline-flex; align-items: center; justify-content: center; gap: 10px; width: 100%; height: 58px; border: 0; border-radius: 14px; font: 700 19px/1 system-ui, -apple-system, "Segoe UI", Roboto, Arial, sans-serif; cursor: pointer; }
.lp-go { background: var(--acc); color: var(--accink); }
.lp-go:hover { filter: brightness(1.06); }
.lp-joinbtn { background: #e9f3ee; color: #0d1f18; }
.lp-joinbtn:disabled { background: #2a4a3d; color: #86a196; cursor: default; }
.lp-btn:focus-visible { outline: 3px solid #fff; outline-offset: 3px; }
.lp-hint { margin: 0; font-size: 15px; color: var(--mute); }
.lp-hint[hidden], .lp-card [hidden] { display: none; }
.lp-courseacts { margin-top: 8px; }
.lp-rec { border-radius: 12px; }
.lp-rec summary { cursor: pointer; padding: 6px 0; color: var(--acc); font-weight: 600; font-size: 16px; list-style: none; display: flex; align-items: center; gap: 8px; }
.lp-rec summary::-webkit-details-marker { display: none; }
.lp-rec summary::before { content: "+"; display: grid; place-items: center; width: 22px; height: 22px; border-radius: 50%; border: 2px solid var(--acc); font-weight: 800; line-height: 1; }
.lp-rec[open] summary::before { content: "\2212"; }
.lp-recbody { display: grid; gap: 8px; padding: 8px 0 4px; }
.lp-minor { font-size: 15px; color: var(--ink); } .lp-minor span { color: var(--mute); }
.lp-err { min-height: 0; margin-top: 12px; color: #ffb4a8; font-size: 15px; }
.lp-err:empty { display: none; }

.lrg-ask { margin-top: 22px; }
.lp-recent { margin-top: 26px; }
.lp-recent h2 { font-size: 17px; margin: 0 0 8px; } .lp-recent h2 span { color: var(--mute); font-weight: 400; font-size: 15px; }
.lp-recent #recentList { display: grid; gap: 8px; }
.lp-recent a { display: flex; align-items: center; gap: 12px; padding: 14px; border-radius: 14px; background: var(--panel); border: 1px solid var(--line); color: var(--ink); text-decoration: none; }
.lp-recent a:hover { border-color: var(--acc); }
.lp-recent strong { flex: 1; min-width: 0; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.lp-recent code { color: var(--mute); font-size: 14px; } .lp-recent time { color: var(--mute); font-size: 13px; }
.lp-foot { display: flex; flex-wrap: wrap; gap: 6px 20px; justify-content: space-between; max-width: 980px; width: 100%; margin: 0 auto; padding: 16px 20px 90px; color: var(--mute); font-size: 14px; border-top: 1px solid var(--line); }
@media (prefers-reduced-motion: reduce) { * { transition: none !important; animation: none !important; } }