/* Hanzhang learner site · home, dated class pages and the hand-in panel. */
:root { --ink: #1b2f36; --muted: #5a6e70; --paper: #f3f6f4; --surface: #fff; --line: #d3e0da; --accent: #25685e; --accent-soft: #e5f1ec; --warn: #8a611c; --warn-soft: #faf1dc; --good: #1f6b43; --good-soft: #e3f2e8; --bad: #9a2f2f; }
* { box-sizing: border-box; }
[hidden] { display: none !important; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--ink); background: var(--paper); font: 16px/1.6 -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", Arial, sans-serif; }
a { color: var(--accent); }
.hz-top { background: var(--ink); color: #fff; }
.hz-top-inner { max-width: 980px; margin: 0 auto; padding: 14px 20px; display: flex; justify-content: space-between; align-items: center; gap: 12px; }
.hz-brand { color: #fff; text-decoration: none; font-weight: 800; letter-spacing: .01em; }
.hz-brand span { color: #a8e0cf; font-weight: 600; }
.hz-page { max-width: 980px; margin: 0 auto; padding: 28px 20px 80px; }
.hz-back { margin: 0 0 18px; font-size: 14px; }
.hz-back a { text-decoration: none; font-weight: 700; }
.hz-kicker { margin: 0; color: var(--accent); font-size: 12px; font-weight: 800; letter-spacing: .14em; text-transform: uppercase; }
.hz-page h1 { margin: 6px 0 8px; font-size: clamp(28px, 5vw, 40px); line-height: 1.12; letter-spacing: -.02em; }
.hz-lead { margin: 0 0 8px; color: var(--muted); }
.hz-section { margin: 30px 0 0; padding: 24px 0 0; border-top: 2px solid var(--line); }
.hz-section > h2 { margin: 0 0 14px; font-size: 22px; }
.hz-empty { margin: 0; padding: 16px 18px; border: 1px dashed var(--line); border-radius: 12px; background: var(--surface); color: var(--muted); }
.hz-cards { display: grid; grid-template-columns: repeat(auto-fill, minmax(270px, 1fr)); gap: 14px; }
.hz-card { display: flex; flex-direction: column; gap: 6px; padding: 18px; border: 1px solid var(--line); border-radius: 14px; background: var(--surface); min-width: 0; }
.hz-card-kind { color: var(--accent); font-size: 12px; font-weight: 800; letter-spacing: .1em; text-transform: uppercase; }
.hz-card h3 { margin: 0; font-size: 19px; line-height: 1.3; }
.hz-meta { margin: 0; color: var(--muted); font-size: 14px; }
.hz-actions { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 8px; }
.hz-btn { display: inline-flex; flex-direction: column; align-items: flex-start; justify-content: center; min-height: 48px; padding: 7px 14px; border: 1px solid var(--accent); border-radius: 10px; background: var(--accent); color: #fff; font: inherit; font-size: 15px; font-weight: 750; line-height: 1.2; text-decoration: none; cursor: pointer; }
.hz-btn small { font-size: 12px; font-weight: 600; opacity: .85; margin-top: 2px; }
.hz-btn.alt { background: #fff; color: var(--accent); }
.hz-btn:hover { filter: brightness(1.06); }
.hz-btn:disabled, .hz-btn[aria-disabled="true"] { opacity: .5; cursor: default; filter: none; }
.hz-btn:focus-visible, .hz-handin summary:focus-visible, .hz-log a:focus-visible { outline: 3px solid #d39a2b; outline-offset: 2px; }
.hz-hw { gap: 8px; }
.hz-hw-grid { display: grid; grid-template-columns: minmax(0, 1fr); gap: 14px; }

/* Home: Class Logbook */
.hz-log { display: grid; gap: 10px; margin: 0; padding: 0; list-style: none; }
.hz-log a { display: grid; grid-template-columns: auto minmax(0, 1fr) auto; gap: 14px; align-items: center; padding: 16px 18px; border: 1px solid var(--line); border-radius: 14px; background: var(--surface); color: var(--ink); text-decoration: none; }
.hz-log a:hover { border-color: var(--accent); }
.hz-log .num { display: grid; place-items: center; width: 52px; height: 52px; border-radius: 12px; background: var(--accent-soft); color: var(--accent); font-weight: 850; font-size: 18px; }
.hz-log strong { display: block; font-size: 17px; }
.hz-log .date { color: var(--muted); font-size: 14px; }
.hz-log .go { color: var(--accent); font-weight: 800; }
.hz-steps { margin: 0; padding-left: 22px; }
.hz-steps li { margin: 6px 0; }
.hz-note { color: var(--muted); font-size: 14px; }

/* Hand-in panel */
.hz-handin { margin-top: 10px; padding: 14px; border-radius: 12px; background: #f7faf8; border: 1px solid var(--line); }
.hz-handin h4 { margin: 0 0 8px; font-size: 15px; }
.hz-status { display: grid; gap: 6px; margin: 0 0 12px; padding: 0; list-style: none; font-size: 14px; }
.hz-status li { display: flex; flex-wrap: wrap; gap: 6px; align-items: baseline; }
.hz-pill { display: inline-flex; padding: 2px 9px; border-radius: 999px; font-size: 12px; font-weight: 800; background: #edf2f0; color: var(--muted); }
.hz-pill.good { background: var(--good-soft); color: var(--good); }
.hz-pill.warn { background: var(--warn-soft); color: var(--warn); }
.hz-options { display: grid; gap: 10px; }
.hz-option { border: 1px solid var(--line); border-radius: 10px; background: #fff; }
.hz-option > summary { display: flex; align-items: center; gap: 10px; padding: 12px 14px; cursor: pointer; font-weight: 750; list-style: none; }
.hz-option > summary::-webkit-details-marker { display: none; }
.hz-option > summary .n { display: grid; place-items: center; width: 26px; height: 26px; flex: none; border-radius: 50%; background: var(--accent-soft); color: var(--accent); font-size: 13px; }
.hz-option > summary small { color: var(--muted); font-weight: 600; }
.hz-option-body { padding: 0 14px 14px; }
.hz-drop { display: grid; place-items: center; gap: 4px; padding: 20px 14px; border: 2px dashed #b9cdc5; border-radius: 12px; background: #fbfdfc; text-align: center; cursor: pointer; }
.hz-drop.is-dragging { border-color: var(--accent); background: var(--accent-soft); }
.hz-drop input { position: absolute; width: 1px; height: 1px; opacity: 0; }
.hz-drop strong { font-size: 15px; }
.hz-drop span { color: var(--muted); font-size: 13px; }
.hz-files { display: grid; gap: 4px; margin: 10px 0 0; padding: 0; list-style: none; font-size: 14px; }
.hz-files li { display: flex; justify-content: space-between; gap: 10px; padding: 6px 10px; border-radius: 8px; background: #f3f6f4; }
.hz-files li span:first-child { overflow-wrap: anywhere; }
.hz-field { display: block; margin: 10px 0 0; font-size: 13px; font-weight: 700; color: var(--muted); }
.hz-field textarea { display: block; width: 100%; min-height: 56px; margin-top: 4px; padding: 8px 10px; border: 1px solid var(--line); border-radius: 8px; font: inherit; font-size: 15px; font-weight: 400; color: var(--ink); }
.hz-msg { min-height: 1.4em; margin: 8px 0 0; font-size: 14px; }
.hz-msg.error { color: var(--bad); }
.hz-msg.success { color: var(--good); font-weight: 700; }
.hz-progress { height: 6px; margin-top: 8px; border-radius: 99px; background: #e4ece8; overflow: hidden; }
.hz-progress i { display: block; height: 100%; width: 0; background: var(--accent); transition: width .2s; }

@media (max-width: 560px) {
  .hz-page { padding: 20px 16px 64px; }
  .hz-log a { grid-template-columns: auto minmax(0, 1fr); }
  .hz-log .go { display: none; }
  .hz-actions .hz-btn { flex: 1 1 140px; }
}
@media print { .hz-top, .hz-handin, .hz-actions { display: none !important; } body { background: #fff; } }