/* Palette: sky-blue background, white cards, royal-blue actions, navy text (her sample, 27 Oct 2026). */
:root {
  --sky-top: #d4e5fb;
  --sky-mid: #e7f1fe;
  --sky-low: #f5f9ff;
  --paper: #ffffff;
  --ink: #0f172a;
  --muted: #64748b;
  --soft-ink: #94a3b8;
  --line: #e2e8f2;
  --soft: #f4f8ff;
  --tint: #e6efff;
  --primary: #1f5fe6;
  --primary-hover: #1749c4;
  --primary-ink: #ffffff;
  --navy: #1d3c9e;
  --ok: #15803d;
  --ok-bg: #e5f6ea;
  --warn: #a16207;
  --warn-bg: #fef3d6;
  --bad: #c2271b;
  --bad-bg: #fde7e4;
  --shadow: 0 1px 2px rgba(15, 23, 42, .04), 0 10px 30px rgba(31, 95, 230, .08);
  color-scheme: light;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --sky-top: #0c1730; --sky-mid: #0b1426; --sky-low: #0a111f;
    --paper: #121b2e; --ink: #e8eefb; --muted: #9aa8c3; --soft-ink: #6f7d99; --line: #24314b;
    --soft: #172238; --tint: #1b2a4a; --primary: #5b8cff; --primary-hover: #7aa2ff; --primary-ink: #0b1226; --navy: #9db8ff;
    --ok: #7fdb9f; --ok-bg: #13321f; --warn: #f5cf6b; --warn-bg: #3a2f10; --bad: #ff9b8f; --bad-bg: #3d1915;
    --shadow: 0 10px 30px rgba(0, 0, 0, .35); color-scheme: dark;
  }
}
:root[data-theme="dark"] {
  --sky-top: #0c1730; --sky-mid: #0b1426; --sky-low: #0a111f;
  --paper: #121b2e; --ink: #e8eefb; --muted: #9aa8c3; --soft-ink: #6f7d99; --line: #24314b;
  --soft: #172238; --tint: #1b2a4a; --primary: #5b8cff; --primary-hover: #7aa2ff; --primary-ink: #0b1226; --navy: #9db8ff;
  --ok: #7fdb9f; --ok-bg: #13321f; --warn: #f5cf6b; --warn-bg: #3a2f10; --bad: #ff9b8f; --bad-bg: #3d1915;
  --shadow: 0 10px 30px rgba(0, 0, 0, .35); color-scheme: dark;
}

* { box-sizing: border-box; }
html { font-size: 16px; }
body {
  margin: 0; color: var(--ink); min-height: 100vh;
  background: linear-gradient(180deg, var(--sky-top) 0%, var(--sky-mid) 340px, var(--sky-low) 900px) fixed;
  font: 1rem/1.55 "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  -webkit-font-smoothing: antialiased;
}
[hidden] { display: none !important; }
h1, h2, h3 { line-height: 1.2; letter-spacing: -0.015em; }
em { font-style: normal; color: var(--muted); font-weight: 400; }

.layout { display: grid; grid-template-columns: 280px 1fr; gap: 0; min-height: 100vh; }

/* Sidebar: a white card, active step as a solid blue pill */
.sidebar {
  position: sticky; top: 16px; align-self: start; height: calc(100vh - 32px); overflow-y: auto;
  margin: 16px 0 16px 16px; padding: 20px 14px; border-radius: 20px;
  background: color-mix(in srgb, var(--paper) 88%, transparent); border: 1px solid var(--line);
  box-shadow: var(--shadow); backdrop-filter: blur(10px);
  display: flex; flex-direction: column; gap: 22px;
}
.brand { display: flex; gap: 12px; align-items: center; padding: 0 4px; }
.brand-logo { background: #fff; border-radius: 12px; padding: 6px 8px; border: 1px solid var(--line); flex: 0 0 auto; }
.brand-logo img { display: block; width: 92px; height: auto; }
.brand h1 { margin: 0; font-size: 1.1rem; font-weight: 700; }
.brand-sub { margin: 2px 0 0; color: var(--muted); font-size: .82rem; }

.steps { display: flex; flex-direction: column; gap: 6px; }
.step {
  display: flex; gap: 12px; align-items: flex-start; text-align: left; width: 100%;
  font: inherit; color: var(--ink); background: transparent; border: 0;
  border-radius: 12px; padding: 10px 12px; cursor: pointer; transition: background .15s;
}
.step:hover { background: var(--tint); }
.step[aria-current="step"] { background: var(--primary); color: var(--primary-ink); box-shadow: 0 6px 16px rgba(31, 95, 230, .25); }
.step .num {
  flex: 0 0 auto; width: 26px; height: 26px; border-radius: 8px; display: grid; place-items: center;
  background: var(--tint); color: var(--primary); font-weight: 700; font-size: .85rem;
}
.step[aria-current="step"] .num { background: var(--primary-ink); color: var(--primary); }
.step b { display: block; font-weight: 600; }
.step small { display: block; color: var(--muted); font-size: .8rem; }
.step[aria-current="step"] small { color: color-mix(in srgb, var(--primary-ink) 80%, transparent); }

.tools { display: flex; flex-direction: column; gap: 10px; padding: 0 4px; }
.tool-row { display: flex; justify-content: space-between; align-items: center; gap: 8px; font-size: .88rem; color: var(--muted); }
.seg { display: inline-flex; border: 1px solid var(--line); border-radius: 10px; overflow: hidden; background: var(--paper); padding: 2px; gap: 2px; }
.seg button { font: inherit; font-size: .82rem; font-weight: 500; border: 0; border-radius: 8px; background: transparent; color: var(--ink); padding: 4px 11px; cursor: pointer; }
.seg button[aria-pressed="true"] { background: var(--primary); color: var(--primary-ink); }
.privacy { margin: auto 0 0; padding: 10px 12px; font-size: .8rem; color: var(--muted); background: var(--soft); border-radius: 12px; }

/* Main */
main { padding: 16px clamp(16px, 4vw, 44px) 64px; max-width: 1120px; width: 100%; }
.panel {
  margin-top: 16px; background: var(--paper); border: 1px solid var(--line); border-radius: 22px;
  padding: 26px clamp(16px, 3vw, 34px); box-shadow: var(--shadow);
}
.panel-head h2 { margin: 10px 0 8px; font-size: clamp(1.6rem, 3vw, 2.1rem); font-weight: 700; }
.panel-head h2 .soft { color: var(--soft-ink); }
.eyebrow {
  display: inline-block; margin: 0; padding: 3px 10px; border-radius: 7px;
  background: var(--primary); color: var(--primary-ink); font-size: .76rem; font-weight: 600;
}
.lead { margin: 0 0 20px; color: var(--muted); max-width: 62ch; }
.panel h3 { margin: 28px 0 6px; font-size: 1.08rem; font-weight: 600; }
.hint { margin: 4px 0 10px; color: var(--muted); font-size: .9rem; }
.panel-foot { margin-top: 26px; padding-top: 18px; border-top: 1px solid var(--line); display: flex; justify-content: flex-end; }

.title-preview {
  border: 1px solid var(--line); background: var(--soft); border-radius: 14px; padding: 12px 16px; margin-bottom: 20px;
  font-weight: 700; color: #c00000; text-align: center;
}
:root[data-theme="dark"] .title-preview { color: #ff8a7a; }
@media (prefers-color-scheme: dark) { :root:not([data-theme="light"]) .title-preview { color: #ff8a7a; } }
.title-preview .label { display: block; font-size: .7rem; text-transform: uppercase; letter-spacing: .08em; color: var(--muted); font-weight: 600; margin-bottom: 2px; }

.grid { display: grid; grid-template-columns: repeat(3, minmax(0, 1fr)); gap: 14px 16px; }
.grid.two { grid-template-columns: 2fr 1fr; }
.field { display: flex; flex-direction: column; gap: 6px; font-size: .88rem; font-weight: 600; }
.field.wide { grid-column: 1 / -1; }
input, select, textarea {
  font: inherit; font-weight: 400; font-size: 1rem; color: var(--ink); background: var(--paper);
  border: 1px solid var(--line); border-radius: 12px; padding: 10px 12px; width: 100%;
  transition: border-color .15s, box-shadow .15s;
}
input::placeholder, textarea::placeholder { color: var(--soft-ink); }
textarea { resize: vertical; min-height: 96px; }
input:focus, select:focus, textarea:focus { outline: none; border-color: var(--primary); box-shadow: 0 0 0 4px color-mix(in srgb, var(--primary) 18%, transparent); }
button:focus-visible, .file-btn:focus-within { outline: 3px solid color-mix(in srgb, var(--primary) 40%, transparent); outline-offset: 2px; }

.btn-row { display: flex; flex-wrap: wrap; gap: 10px; align-items: center; margin: 12px 0 0; }
.btn {
  font: inherit; font-weight: 600; font-size: .93rem; border-radius: 12px; padding: 10px 18px; cursor: pointer;
  border: 1px solid transparent; display: inline-flex; align-items: center; gap: 6px; text-decoration: none;
  transition: background .15s, box-shadow .15s, transform .05s;
}
.btn:active { transform: translateY(1px); }
.btn.primary { background: var(--primary); color: var(--primary-ink); box-shadow: 0 6px 16px rgba(31, 95, 230, .22); }
.btn.primary:hover { background: var(--primary-hover); }
.btn.secondary { background: var(--paper); color: var(--primary); border-color: color-mix(in srgb, var(--primary) 45%, var(--line)); }
.btn.secondary:hover { background: var(--tint); }
.btn.ghost { background: transparent; color: var(--ink); border-color: var(--line); }
.btn.ghost:hover { background: var(--soft); }
.btn.danger { color: var(--bad); }
.btn:disabled { opacity: .5; cursor: progress; }
.file-btn { position: relative; overflow: hidden; }
.file-btn input { position: absolute; inset: 0; opacity: 0; cursor: pointer; }

.logo-row { display: flex; gap: 18px; align-items: center; flex-wrap: wrap; }
.logo-frame { background: #fff; border: 1px solid var(--line); border-radius: 16px; padding: 8px; box-shadow: var(--shadow); }
.logo-frame img { display: block; width: 110px; height: 110px; object-fit: contain; }

/* Students */
.paste-box { margin-top: 14px; padding: 16px; border: 1px dashed color-mix(in srgb, var(--primary) 40%, var(--line)); border-radius: 16px; background: var(--soft); }
.students { display: grid; grid-template-columns: 270px 1fr; gap: 20px; margin-top: 20px; align-items: start; }
.student-list { list-style: none; margin: 0; padding: 0; display: flex; flex-direction: column; gap: 4px; max-height: 70vh; overflow-y: auto; }
.student-list button {
  width: 100%; text-align: left; font: inherit; color: var(--ink); background: transparent; cursor: pointer;
  border: 1px solid transparent; border-radius: 12px; padding: 9px 11px; display: flex; justify-content: space-between; gap: 8px; align-items: center;
}
.student-list button:hover { background: var(--soft); }
.student-list button[aria-current="true"] { background: var(--tint); border-color: color-mix(in srgb, var(--primary) 30%, var(--line)); }
.student-list .who { min-width: 0; }
.student-list .who b { display: block; font-weight: 600; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
.student-list .who small { color: var(--muted); }
.badge { flex: 0 0 auto; font-size: .72rem; font-weight: 600; border-radius: 7px; padding: 3px 8px; white-space: nowrap; }
.badge.ok { background: var(--ok-bg); color: var(--ok); }
.badge.todo { background: var(--warn-bg); color: var(--warn); }
.badge.bad { background: var(--bad-bg); color: var(--bad); }
.empty { color: var(--muted); }

.editor { border: 1px solid var(--line); border-radius: 18px; padding: 20px; background: var(--paper); box-shadow: var(--shadow); container-type: inline-size; }
@container (max-width: 620px) {
  .score-row { grid-template-columns: 1fr auto; }
  .score-row .detail { grid-column: 1 / -1; }
}
.warn { margin: 8px 0 0; color: var(--bad); font-size: .9rem; font-weight: 600; }
.scores { display: flex; flex-direction: column; gap: 10px; margin: 18px 0; }
.score-row { display: grid; grid-template-columns: 170px 120px 1fr; gap: 12px; align-items: start; padding: 12px 14px; border-radius: 14px; background: var(--soft); border: 1px solid var(--line); }
.score-row .area { font-weight: 600; }
.score-row .area small { display: block; font-weight: 400; color: var(--muted); }
.score-in { display: flex; align-items: center; gap: 6px; }
.score-in input { width: 76px; text-align: center; font-weight: 700; }
.score-in span { color: var(--muted); white-space: nowrap; }
.score-row.bad input { border-color: var(--bad); }
.lvl { display: inline-block; font-size: .78rem; font-weight: 600; padding: 3px 9px; border-radius: 7px; background: var(--line); color: var(--muted); }
.lvl.l0, .lvl.l1 { background: var(--ok-bg); color: var(--ok); }
.lvl.l2 { background: var(--warn-bg); color: var(--warn); }
.lvl.l3, .lvl.l4 { background: var(--bad-bg); color: var(--bad); }
.statement { margin: 6px 0 0; font-size: .87rem; color: var(--muted); }

.totals { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; margin: 0 0 18px; }
.totals div { border: 1px solid var(--line); border-radius: 14px; padding: 10px 14px; background: var(--paper); }
.totals span { display: block; font-size: .78rem; color: var(--muted); }
.totals b { font-size: 1.35rem; font-weight: 700; }
.totals .grade { color: var(--primary); }
.nav-row { justify-content: space-between; border-top: 1px solid var(--line); padding-top: 14px; margin-top: 16px; }

/* Download */
.not-ready { margin: 0 0 8px; padding-left: 20px; color: var(--muted); }
.not-ready a { color: var(--primary); }
.cards { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; margin-top: 8px; }
.card { border: 1px solid var(--line); border-radius: 18px; padding: 18px; background: var(--paper); box-shadow: var(--shadow); }
.card:first-child { background: linear-gradient(160deg, #3f7bff 0%, #1f5fe6 70%); border-color: transparent; color: #fff; }
.card:first-child p { color: rgba(255, 255, 255, .85); }
.card:first-child .btn.primary { background: #fff; color: #1f5fe6; box-shadow: none; }
.card h3 { margin: 0 0 6px; }
.card p { margin: 0 0 14px; color: var(--muted); font-size: .92rem; }

/* Preview */
dialog {
  width: min(900px, 96vw); height: min(92vh, 1100px); border: 1px solid var(--line); border-radius: 20px; padding: 0;
  background: var(--paper); color: var(--ink); box-shadow: 0 30px 80px rgba(15, 23, 42, .35);
}
dialog[open] { display: flex; flex-direction: column; }
dialog::backdrop { background: rgba(15, 23, 42, .5); backdrop-filter: blur(2px); }
.dialog-head { display: flex; justify-content: space-between; align-items: center; gap: 10px; padding: 12px 16px; border-bottom: 1px solid var(--line); flex-wrap: wrap; }
.dialog-head h2 { margin: 0; font-size: 1.02rem; }
.dialog-head .btn-row { margin: 0; }
dialog iframe { flex: 1; width: 100%; border: 0; background: #fff; border-radius: 0 0 20px 20px; }

.toast {
  position: fixed; left: 50%; bottom: 22px; transform: translateX(-50%); max-width: min(560px, 92vw);
  background: var(--ink); color: var(--paper); padding: 11px 16px; border-radius: 12px; box-shadow: var(--shadow); z-index: 10; font-size: .93rem;
}

/* Tablet and phone */
@media (max-width: 980px) {
  .students { grid-template-columns: 1fr; }
  .student-list { max-height: 260px; }
}
@media (max-width: 860px) {
  .layout { grid-template-columns: 1fr; }
  .sidebar { position: static; height: auto; margin: 16px 16px 0; }
  .privacy { margin: 0; }
}
@media (max-width: 640px) {
  .grid, .grid.two { grid-template-columns: 1fr; }
  .score-row { grid-template-columns: 1fr auto; }
  .score-row .detail { grid-column: 1 / -1; }
  .totals { grid-template-columns: 1fr 1fr 1fr; }
  .totals b { font-size: 1.1rem; }
  .cards { grid-template-columns: 1fr; }
  .panel { border-radius: 18px; }
  .nav-row .danger { width: 100%; justify-content: center; }
}