:root {
  color-scheme: light dark;

  /* Colors — every color in this file goes through these variables;
     the dark block below overrides them for prefers-color-scheme: dark. */
  --text: #222;
  --muted: #666;
  --border: #ccc;
  --background: #fff;
  --subtle: #f6f6f6;
  --surface: #fff;          /* inputs, light buttons */
  --hover: #eee;
  --selected: #ddd;
  --control-border: #999;   /* inputs and buttons — darker than --border for affordance */
  --link: #1259a7;
  --primary-bg: #222;
  --primary-fg: #fff;
  --primary-hover: #444;
  --danger: #b44;
  --danger-subtle: #fff1f1;
  --success: #8aab85;
  --success-subtle: #f0f7ef;

  /* Type scale — the only font sizes used anywhere:
     sm   secondary text: nav, hints, meta, counters, tags, summaries
     base body copy, form controls, h3
     lg   section headings (h2, direction titles)
     xl   page titles (h1) */
  --text-sm: 14px;
  --text-base: 16px;
  --text-lg: 20px;
  --text-xl: 28px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --text: #e3e3e3;
    --muted: #9d9d9d;
    --border: #3d3d3d;
    --background: #161616;
    --subtle: #1f1f1f;
    --surface: #1c1c1c;
    --hover: #333;
    --selected: #4a4a4a;
    --control-border: #666;
    --link: #8ab4f8;
    --primary-bg: #e3e3e3;
    --primary-fg: #161616;
    --primary-hover: #fff;
    --danger: #d98181;
    --danger-subtle: #341c1c;
    --success: #6b8f66;
    --success-subtle: #1c271a;
  }
}

* { box-sizing: border-box; }
body { margin: 0; background: var(--background); color: var(--text); font: var(--text-base)/1.5 system-ui, sans-serif; }
a { color: var(--link); }
button, input, textarea { font: inherit; }
.page-shell { width: min(900px, calc(100% - 32px)); margin: 0 auto; }

.site-header { border-bottom: 1px solid var(--border); padding: 16px max(16px, calc((100% - 900px) / 2)); }
.brand { align-items: center; color: var(--text); display: flex; font-weight: 600; gap: 8px; text-decoration: none; }
.brand-logo { height: 22px; width: 22px; }
.site-header { align-items: center; display: flex; justify-content: space-between; }
.session-nav { align-items: center; display: flex; gap: 12px; font-size: var(--text-sm); }
.session-nav form { display: inline; }
.session-nav button { background: none; border: 0; color: var(--link); cursor: pointer; padding: 0; text-decoration: underline; }
main { min-height: calc(100vh - 120px); }
footer { border-top: 1px solid var(--border); color: var(--muted); font-size: var(--text-sm); padding: 20px 16px; text-align: center; }

h1 { font-size: var(--text-xl); line-height: 1.2; margin: 0 0 12px; }
h2 { font-size: var(--text-lg); margin: 0 0 16px; }
h3 { font-size: var(--text-base); margin: 0 0 6px; }
p { margin: 0 0 12px; }
.hero { padding-top: 56px; }
.hero-copy, .form-intro p { color: var(--muted); }
.tool-section { padding: 48px 0 80px; }
.tool-card { align-items: center; border: 1px solid var(--border); display: flex; justify-content: space-between; gap: 24px; padding: 20px; }
.tool-card p { color: var(--muted); margin: 0; }
.tool-card + .tool-card { margin-top: 16px; }
.live-hint { color: var(--muted); font-size: var(--text-sm); margin: 16px 0 0; }
.more-details { margin: 4px 0 16px; }
.more-details summary { color: var(--link); cursor: pointer; font-size: var(--text-sm); margin-bottom: 12px; text-decoration: underline; }
.claim-details { margin-top: 10px; }
.claim-details summary { color: var(--link); cursor: pointer; font-size: var(--text-sm); text-decoration: underline; }
.planned-heading { margin-top: 48px; }
.tool-card-planned { background: var(--subtle); border-style: dashed; }
.tool-card-planned h3 { color: var(--muted); }
.planned-tag { border: 1px solid var(--border); border-radius: 4px; color: var(--muted); font-size: var(--text-sm); padding: 4px 10px; white-space: nowrap; }

.button { background: var(--subtle); border: 1px solid var(--control-border); border-radius: 4px; color: var(--text); cursor: pointer; display: inline-block; font-weight: 500; padding: 9px 14px; text-decoration: none; }
.button:hover { background: var(--hover); }
.button-primary { background: var(--primary-bg); border-color: var(--primary-bg); color: var(--primary-fg); }
.button-primary:hover { background: var(--primary-hover); }
.button-light, .button-outline { background: var(--surface); }
.button-danger { background: var(--surface); border-color: var(--danger); color: var(--danger); }
.button-danger:hover { background: var(--danger-subtle); }
.danger-zone { border-top: 1px solid var(--border); margin-top: 40px; padding-top: 20px; }
.past-carpools { margin-top: 16px; }
.past-carpools summary { color: var(--muted); cursor: pointer; font-size: var(--text-sm); margin-bottom: 12px; }
.back-link { display: inline-block; margin-bottom: 28px; }

.form-page { padding: 40px 0 80px; }
.form-page.narrow { max-width: 760px; }
.paper-form, .join-panel { border: 1px solid var(--border); margin-top: 28px; padding: 24px; }
.field { margin-bottom: 18px; }
.field label { display: block; font-weight: 600; margin-bottom: 6px; }
.field input, .field textarea { background: var(--surface); border: 1px solid var(--control-border); border-radius: 3px; color: var(--text); padding: 9px 10px; width: 100%; }
.field input:focus, .field textarea:focus { border-color: var(--text); outline: 2px solid var(--border); }
.form-submit { display: flex; align-items: center; gap: 16px; }
.form-hint { color: var(--muted); font-size: var(--text-sm); margin: -6px 0 16px; }
.account-section { margin-top: 40px; }
.error-box { background: var(--danger-subtle); border: 1px solid var(--danger); margin-bottom: 18px; padding: 10px; }
.flash { padding-top: 20px; }
.flash .notice, .flash .error-box { margin-bottom: 0; }

.board-hero { border-bottom: 1px solid var(--border); padding: 32px 0; }
.board-hero .back-link { margin-bottom: 20px; }
.board-title { align-items: start; display: flex; justify-content: space-between; gap: 20px; }
.board-title-actions { display: flex; gap: 8px; }
.board-title h1 { margin-bottom: 0; }
.trip-facts { display: grid; gap: 18px; grid-template-columns: repeat(3, 1fr); margin-top: 24px; }
.trip-facts small { color: var(--muted); display: block; font-size: var(--text-sm); margin-bottom: 3px; }
.trip-facts strong { font-weight: 500; }
.board-body { padding: 28px 0 80px; }
.direction-section + .direction-section { border-top: 1px solid var(--border); margin-top: 48px; padding-top: 40px; }
.direction-title { font-size: var(--text-lg); }
.column-title h3 { margin: 0; }
.notice { background: var(--success-subtle); border: 1px solid var(--success); margin-bottom: 20px; padding: 10px 12px; }
.board-actions { align-items: center; display: flex; gap: 10px; margin-bottom: 32px; }

.ride-columns { display: grid; grid-template-columns: 1fr 1fr; gap: 28px; }
.column-title { align-items: center; display: flex; justify-content: space-between; margin-bottom: 10px; }
.column-title h2 { margin: 0; }
.column-title b { color: var(--muted); font-size: var(--text-sm); font-weight: 500; }
.ride-card, .empty-card { border: 1px solid var(--border); margin-bottom: 10px; padding: 16px; }
.empty-card { background: var(--subtle); color: var(--muted); }
.empty-card p { margin: 0; }
.ride-top { display: flex; justify-content: space-between; gap: 16px; }
.ride-top > span { color: var(--muted); font-size: var(--text-sm); }
.route { margin-bottom: 4px; }
.route span, .meta, .contact { color: var(--muted); font-size: var(--text-sm); }
.notes { margin: 10px 0; }
.contact { margin: 8px 0; }
.owner-actions { border-top: 1px solid var(--border); display: flex; gap: 12px; margin-top: 12px; padding-top: 10px; }
.owner-actions a, .owner-actions button { background: none; border: 0; color: var(--link); cursor: pointer; font-size: var(--text-sm); padding: 0; text-decoration: underline; }
.owner-actions form { display: inline; }
.passengers { border-top: 1px solid var(--border); margin-top: 12px; padding-top: 10px; }
.passengers strong { font-size: var(--text-sm); }
.passengers ul { list-style: none; margin: 6px 0 0; padding: 0; }
.passengers li { align-items: center; display: flex; font-size: var(--text-sm); justify-content: space-between; padding: 3px 0; }
.passengers form { display: inline; }
.passengers button { background: none; border: 0; color: var(--link); cursor: pointer; font-size: var(--text-sm); padding: 0; text-decoration: underline; }
.full-label { color: var(--muted); font-size: var(--text-sm); margin: 12px 0 0; }
.offer-banner { background: var(--subtle); border: 1px solid var(--border); margin-top: 12px; padding: 12px; }
.offer-banner form { display: inline-block; margin-right: 8px; }
.claim-form { background: var(--subtle); border: 1px solid var(--border); margin: 10px 0 0; padding: 14px; }
.claim-form .field { margin-bottom: 12px; }
.claim-form .button { margin-right: 10px; }

.join-panel { display: grid; grid-template-columns: 200px 1fr; gap: 32px; margin-top: 40px; }
.join-panel > :only-child { grid-column: 1 / -1; }
.join-copy p { color: var(--muted); }
.form-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 0 18px; }
.form-grid .wide { grid-column: 1 / -1; }
.role-toggle { display: flex; margin-bottom: 20px; }
.role-toggle label { flex: 1; }
.role-toggle input { position: absolute; opacity: 0; }
.role-toggle span { border: 1px solid var(--control-border); cursor: pointer; display: block; padding: 9px; text-align: center; }
.role-toggle label + label span { border-left: 0; }
.role-toggle input:checked + span { background: var(--selected); font-weight: 600; }
.ride-form > .button { margin-top: 4px; }

@media (max-width: 680px) {
  .tool-card, .board-title, .board-actions { align-items: flex-start; flex-direction: column; }
  .trip-facts, .ride-columns, .join-panel, .form-grid { grid-template-columns: 1fr; }
  .form-grid .wide { grid-column: auto; }
  .join-panel { gap: 12px; }
}