:root {
  color-scheme: light;
  --ink: #233a37;
  --muted: #536864;
  --accent: #126f60;
  --accent-hover: #0b5145;
  --on-accent: #fff;
  --visited: #66518c;
  --canvas: #f7f9f6;
  --surface: #fff;
  --surface-raised: #edf4ee;
  --line: #d5e1d8;
  --control-line: #788f85;
  --focus: #1666b0;
  --success: #167139;
  --success-bg: #e8f5e9;
  --error: #a4262c;
  --error-bg: #fff0f0;
  --tooltip-surface: #233a37;
  --tooltip-ink: #fff;
  --intro: #e9f5e9;
  --radius: 1rem;
}
:root[data-theme="midnight"] {
  color-scheme: dark;
  --ink: #f4f5f9;
  --muted: #bcc5dc;
  --accent: #c7ed72;
  --accent-hover: #daff92;
  --on-accent: #131725;
  --visited: #c9baff;
  --canvas: #131725;
  --surface: #1b2133;
  --surface-raised: #252d46;
  --line: #3d4963;
  --control-line: #7889aa;
  --focus: #9dccff;
  --success: #9de0ae;
  --success-bg: #203e35;
  --error: #ffb4b4;
  --error-bg: #482b38;
  --tooltip-surface: #e7ecf8;
  --tooltip-ink: #171d2d;
  --intro: #252d46;
  --radius: .65rem;
}
body { background: var(--canvas); color: var(--ink); font-family: ui-rounded, "SF Pro Rounded", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; line-height: 1.5; }
a { color: var(--accent); text-underline-offset: .2em; }
a:visited { color: var(--visited); }
a:hover { color: var(--accent-hover); }
h1, h2, h3 { line-height: 1.2; letter-spacing: -.025em; }
h1 { font-size: clamp(1.7rem, 3vw, 2.4rem); margin: 1.25rem 0; }
h2 { font-size: 1.35rem; }
body > header { align-items: center; gap: .75rem 1.25rem; padding: .85rem 2rem; background: var(--surface); border-bottom: 1px solid var(--line); flex-shrink: 0; }
.breadcrumb { font-size: .9rem; }
.account-nav { font-size: .9rem; }
.account-nav a { display: inline-block; padding: .5rem; }
#main-content { padding: 1rem 2rem 2rem; min-width: 0; }
body > .reading-footer { background: var(--surface); border-color: var(--line); }
body:has(.learning-hub) > .reading-footer { position: static; }
.footer-about { padding: .25rem 0; }
button, input, select, textarea { font: inherit; }
button, .btn { border: 1px solid var(--control-line); border-bottom-width: 3px; border-radius: .6rem; background: var(--surface); color: var(--ink); cursor: pointer; padding: .45em .9em; }
/* Low specificity keeps graded answers and individual letter slots authoritative. */
:where(button):hover:where(:not(:disabled):not([aria-disabled="true"]):not(.correct):not(.incorrect):not(.gap)) { background: var(--surface-raised); }
button:disabled, button[aria-disabled="true"] { cursor: default; }
button:disabled { opacity: .65; }
#submit, #forward, #yes, #show-btn, button[type="submit"]:not(.link-button) { background: var(--accent); border-color: var(--accent); color: var(--on-accent); font-weight: 700; }
#submit:hover, #forward:hover, #yes:hover, #show-btn:hover, button[type="submit"]:not(.link-button):hover { background: var(--accent-hover); }
button.link-button { border: 0; border-radius: 0; background: none; color: var(--accent); }
:where(a, button, input, select, textarea, summary, [tabindex]):where(:not(.gap)):focus-visible { outline: 3px solid var(--focus); outline-offset: 3px; }
body > a.sr-only:focus { display: block; background: var(--surface); padding: .8rem 1rem; }
input:not(.gap):not([type="radio"]):not([type="checkbox"]):not([type="hidden"]):not([type="submit"]), select, textarea { box-sizing: border-box; max-width: 100%; border: 1px solid var(--control-line); border-radius: .5rem; background: var(--surface); color: var(--ink); padding: .4rem .6rem; }
input[type="radio"], input[type="checkbox"] { accent-color: var(--accent); }
input.gap { color: var(--ink); }
fieldset { min-width: 0; border: 1px solid var(--line); border-radius: var(--radius); background: var(--surface); padding: 1rem; margin: 0 0 1rem; }
legend { font-weight: 700; padding: 0 .4rem; }
fieldset label { display: inline-block; margin: .3rem .75rem .3rem 0; }
.errorlist, .form-errors { color: var(--error); }
#submit-controls, #self-assess-controls, #controls { flex-wrap: wrap; }
#instructions { color: var(--muted); max-width: 65ch; }
#result:not(:empty):not(.sr-only) { border: 1px solid var(--line); border-radius: .75rem; background: var(--surface); padding: 1rem; max-width: 65ch; }
.flashcard-panel { background: var(--surface); border: 1px solid var(--control-line); border-bottom-width: 4px; border-radius: var(--radius); box-shadow: none; }
.flashcard-back-panel { background: var(--surface-raised); }
dialog { color: var(--ink); background: var(--surface); border: 1px solid var(--control-line); }
#session-complete-modal, #group-complete-modal { background: var(--surface); color: var(--ink); }
#theme-switch { display: inline-flex; align-items: center; gap: .6rem; font-size: .85rem; padding: .45rem .7rem; white-space: nowrap; border-bottom-width: 1px; }
#theme-switch[hidden] { display: none; }
#theme-switch::before { content: ""; width: 1.8rem; height: 1rem; border: 1px solid var(--control-line); border-radius: 1rem; background: radial-gradient(circle at .5rem center, var(--muted) .32rem, transparent .35rem) var(--surface-raised); }
#theme-switch[aria-checked="true"]::before { background: radial-gradient(circle at 1.3rem center, var(--on-accent) .32rem, transparent .35rem) var(--accent); border-color: var(--accent); }
#hittite-sidebar { background: var(--surface); border-color: var(--line); }
#hittite-sidebar a { text-underline-offset: .15em; }
#hittite-sidebar li { margin-top: .35rem; }
#hittite-sidebar-toggle, #hittite-drawer-close { background: var(--surface); color: var(--ink); }
#hittite-lessons-button { padding: .15rem .5rem; line-height: 1.1; }
.learning-hub { max-width: 1040px; margin: 0 auto; padding: 1.3rem 0 2rem; }
.learning-hub .hub-intro { padding: 2.4rem; background: var(--intro); border: 1px solid var(--line); border-radius: var(--radius); margin: 0 0 2.5rem; font-size: clamp(2rem, 4vw, 3.4rem); }
[data-theme="midnight"] .learning-hub .hub-intro { box-shadow: inset 4px 0 var(--accent); }
.learning-hub section { margin-bottom: 2.5rem; }
.learning-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(min(100%, 15rem), 1fr)); gap: 1.1rem; padding: 0; margin: 1.25rem 0; list-style: none; }
.learning-grid li { min-width: 0; }
.learning-grid a, .learning-grid a:visited { height: 100%; box-sizing: border-box; display: flex; align-items: center; padding: 1.8rem 1.5rem; color: var(--ink); background: var(--surface); border: 1px solid var(--line); border-bottom: 4px solid var(--line); border-radius: var(--radius); text-decoration: none; font-weight: 700; }
.learning-grid a:hover { color: var(--accent); background: var(--surface-raised); border-color: var(--control-line); }
#main-content #lesson-list { list-style: none; padding: 0; }
#main-content #lesson-list > li { padding: 1.15rem 1.3rem; background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius); margin-bottom: 1rem; }
#main-content #lesson-list > li > a:first-child { font-weight: 700; }
#main-content #lesson-list > li > ul { margin-top: .6rem; }
#page-header { background: var(--surface); }
#page-header h1 { padding-top: .6rem; }
#reading-content { background: var(--canvas); }
@media (min-height: 401px) {
  #reading-content { min-height: min(12rem, 35vh); }
}
#reading-content .line { padding: .7rem 0 1rem; border-bottom: 1px solid var(--line); margin-bottom: .5rem; }
#reading-content .line-body { min-width: 0; }
#reading-content .word-pair { margin-bottom: .25rem; }
#export-pdf-link { align-self: flex-end; }
#advanced-options, .filter-box, .ms-filters { border-radius: .65rem; }
#keyboard, #special-keyboard, #tray { border-radius: .75rem; }
/* Keep glyph focus rings clear of answer fields and adjacent selected keys. */
.sign-box { gap: .5rem; }
#special-keyboard, .keyboard-row, #options { gap: .75rem; }
.keyboard-row { margin-bottom: .75rem; }
.distractor-keys { gap: .5rem; }
@media (max-width: 700px) {
  body > header { padding: .6rem 1rem; gap: .4rem .75rem; }
  body > header > nav[aria-label="Breadcrumb"] { flex-basis: 100%; }
  #main-content { padding: 1rem; }
  .learning-hub { padding-top: .5rem; }
  .learning-hub .hub-intro { padding: 1.5rem; margin-bottom: 2rem; }
  .learning-grid a { padding: 1.3rem; }
  .reading-nav { gap: .5rem; }
  .dropdown-row { flex-wrap: wrap; }
  #page-header .dropdown-group { gap: .5rem; }
  #page-header #controls { margin-top: .5rem; }
  #reading-content { padding: .75rem; }
  #hittite-sidebar li { margin-top: .3rem; }
}
@media (prefers-reduced-motion: reduce) {
  .flashcard-card.revealed .flashcard-back-panel { animation: none; }
}

@media (max-width: 700px) {
  .table-scroll { max-width: 100%; overflow-x: auto; }
  .texts-main { max-width: 100%; }
  .texts-main .table-scroll { max-height: 70vh; }
  .texts-main .ms-table thead th { top: 0; }
  .filter-bar { flex-wrap: wrap; }
  .ms-filters, .ms-filters fieldset { min-width: 0; }
  .ms-field { max-width: 100%; }
  .filter-box { flex: 0 1 auto; max-width: 100%; }
}