* { box-sizing: border-box; }

:root {
  color-scheme: dark;
  font-family: "Segoe UI", "Yu Gothic UI", "Meiryo", sans-serif;
}

html, body { margin: 0; min-width: 320px; min-height: 100%; }
body {
  min-height: 100vh;
  background: radial-gradient(circle at center, #17243a 0%, #070b12 60%, #000 100%);
  color: #f7f9ff;
  overflow-x: hidden;
}
button, input, select { font: inherit; -webkit-tap-highlight-color: transparent; }
button { cursor: pointer; }
input, select {
  width: 100%; min-height: 48px; border: 1px solid rgba(139,183,245,.5); border-radius: 12px;
  background: rgba(8,17,31,.9); color: #f7f9ff; outline: none;
}
input { padding: 10px 12px; }
select { padding: 10px 38px 10px 12px; }
input:focus, select:focus { border-color:#8fbaff; box-shadow:0 0 0 3px rgba(93,147,255,.2); }

.app-shell { width:min(1920px,100%); min-height:100vh; margin:0 auto; padding:clamp(14px,2vw,32px); }
.screen[hidden], .timer-section[hidden], .timer-settings-list[hidden], [hidden] { display:none !important; }

.page-header { margin-bottom:clamp(18px,2vw,30px); text-align:center; }
.page-header h1, .page-header p, .section-heading h2 { margin:0; }
.page-header h1 { font-size:clamp(1.8rem,3vw,3.1rem); }
.page-header p { margin-top:7px; color:#aebfd8; font-size:clamp(.9rem,1.2vw,1.15rem); }
.board-header { margin-bottom:clamp(10px,1.2vw,18px); }

.setup-form { display:grid; gap:clamp(20px,2.4vw,34px); }
.setup-group { padding:clamp(16px,2vw,28px); border:1px solid rgba(151,190,245,.35); border-radius:22px; background:linear-gradient(145deg,rgba(23,39,63,.88),rgba(7,13,24,.93)); box-shadow:0 0 28px rgba(85,139,226,.12); }
.setup-group-header { display:grid; grid-template-columns:minmax(0,1fr) minmax(140px,200px); gap:18px; margin-bottom:18px; }
.field-block { display:grid; gap:7px; }
.field-block label { color:#dbe8fb; font-weight:700; }
.count-note { margin:2px 0 0; color:#9fb2ce; font-size:.78rem; line-height:1.35; }
.timer-settings-list { display:grid; gap:12px; }
.timer-setting-row { display:grid; grid-template-columns:minmax(0,1fr) auto; align-items:end; gap:16px; padding:14px; border:1px solid rgba(131,169,224,.22); border-radius:16px; background:rgba(5,12,23,.48); }
.duration-fields, .extension-duration-row { display:grid; grid-template-columns:repeat(2,minmax(90px,110px)); gap:10px; }
.setup-error { min-height:1.5em; margin:-2px 0 0; color:#ff9b9b; font-weight:700; text-align:center; }
.setup-actions { display:flex; justify-content:center; padding-bottom:20px; }
.setup-subheading { margin:0 0 14px; font-size:clamp(1.2rem,1.8vw,1.6rem); }
.board-title-setup { background:linear-gradient(145deg,rgba(22,36,58,.9),rgba(7,13,24,.94)); }

.primary-button, .secondary-button { min-height:48px; padding:10px 20px; border:1px solid #84b6ff; border-radius:14px; color:#eef5ff; font-weight:700; }
.primary-button { background:linear-gradient(145deg,#376cff,#1541b8); box-shadow:0 0 18px rgba(71,126,255,.35), inset 0 0 10px rgba(255,255,255,.1); }
.secondary-button { border-color:rgba(151,184,227,.58); background:rgba(21,34,54,.95); box-shadow:inset 0 0 10px rgba(122,169,236,.08); }
.primary-button:hover:not(:disabled), .primary-button:focus-visible:not(:disabled), .secondary-button:hover:not(:disabled), .secondary-button:focus-visible:not(:disabled) { filter:brightness(1.14); outline:3px solid rgba(155,198,255,.32); outline-offset:3px; }
button:disabled { cursor:not-allowed; opacity:.35; }
.create-board-button { width:min(440px,100%); min-height:56px; font-size:clamp(1.05rem,1.7vw,1.45rem); }

.timer-section { margin-bottom:clamp(12px,1.4vw,22px); padding:clamp(10px,1vw,18px); border:1px solid rgba(166,198,241,.18); border-radius:clamp(16px,1.5vw,24px); }
.timer-section-upper { background:linear-gradient(145deg,rgba(38,88,150,.14),rgba(7,13,24,.38)); }
.timer-section-lower { background:linear-gradient(145deg,rgba(92,57,137,.14),rgba(7,13,24,.38)); }
.timer-section-extension { background:linear-gradient(145deg,rgba(170,117,28,.18),rgba(30,21,6,.46)); border-color:rgba(239,188,87,.24); }

.extension-timer-panel.extension-base-upper .timer-face {
  background:linear-gradient(145deg,rgba(35,70,118,.96),rgba(8,18,34,.97));
  border-color:rgba(132,181,247,.62);
  box-shadow:0 0 24px rgba(71,137,225,.18), inset 0 0 24px rgba(111,170,245,.09);
}

.extension-timer-panel.extension-base-lower .timer-face {
  background:linear-gradient(145deg,rgba(78,50,112,.96),rgba(18,10,30,.97));
  border-color:rgba(178,135,226,.55);
  box-shadow:0 0 24px rgba(129,79,184,.18), inset 0 0 24px rgba(171,119,224,.09);
}
.section-heading { margin-bottom:8px; }
.section-heading h2 { font-size:clamp(1.35rem,2vw,2.2rem); line-height:1.1; overflow-wrap:anywhere; }
.timer-grid { display:grid; grid-template-columns:repeat(var(--timer-count,4),minmax(0,1fr)); gap:clamp(8px,1vw,16px); }
.timer-panel { min-width:0; perspective:1200px; transition:opacity .35s ease; }
.timer-panel-inner { display:grid; width:100%; min-height:clamp(180px,18vw,300px); transform-style:preserve-3d; transition:transform .7s ease-in-out; }
.timer-panel.is-finished { opacity:.7; }
.timer-panel.is-finished .timer-panel-inner { transform:rotateY(180deg); }
.timer-face { grid-area:1/1; display:grid; width:100%; padding:clamp(10px,1vw,18px); border:1px solid rgba(182,211,255,.55); border-radius:clamp(16px,1.5vw,26px); background:linear-gradient(145deg,rgba(32,50,78,.92),rgba(6,12,23,.96)); box-shadow:0 0 24px rgba(116,168,255,.16), inset 0 0 24px rgba(158,200,255,.08); text-align:center; backface-visibility:hidden; -webkit-backface-visibility:hidden; }
.timer-face-front { align-content:center; gap:clamp(8px,1vw,16px); }
.timer-face-back { align-content:center; justify-items:center; gap:14px; transform:rotateY(180deg); }
.timer-title { max-width:100%; margin:0; color:#eef5ff; font-size:clamp(1.15rem,2vw,2.25rem); font-weight:800; line-height:1.05; text-shadow:0 0 16px rgba(159,198,255,.36); overflow-wrap:anywhere; }
.time-display { display:grid; grid-template-columns:minmax(0,1fr) auto minmax(0,1fr); align-items:center; width:100%; }
.minutes-display, .seconds-display, .time-colon { color:#fff; font-family:Consolas,"Roboto Mono","Courier New",monospace; font-weight:700; line-height:.9; text-shadow:0 0 11px rgba(255,255,255,.52),0 0 26px rgba(153,194,255,.22); transition:color .2s ease,text-shadow .2s ease; }
.minutes-display, .seconds-display { min-width:0; font-size:clamp(3.2rem,6.7vw,7.3rem); letter-spacing:-.09em; }
.time-colon { padding:0 .02em .08em; font-size:clamp(2.4rem,4.3vw,4.8rem); }
.time-display.is-warning .minutes-display, .time-display.is-warning .seconds-display, .time-display.is-warning .time-colon { color:#ff4b4b; text-shadow:0 0 11px rgba(255,75,75,.68),0 0 28px rgba(255,0,0,.24); }
.finished-message { display:grid; justify-items:center; gap:8px; width:100%; }
.finished-title, .finished-text { max-width:100%; margin:0; color:#fff; font-weight:800; line-height:1.05; overflow-wrap:anywhere; text-shadow:0 0 14px rgba(255,255,255,.4),0 0 28px rgba(153,194,255,.24); }
.finished-title { font-size:clamp(1.5rem,2.4vw,2.8rem); }
.finished-text { font-size:clamp(2.8rem,4.7vw,5.2rem); letter-spacing:.08em; }
.extension-info { display:grid; gap:2px; }
.extension-history,
.extension-total { margin:0; color:#f6d88d; font-size:clamp(.68rem,.9vw,.88rem); font-weight:700; line-height:1.25; overflow-wrap:anywhere; }
.extension-total { color:#ffe6a8; }
.extension-panel-actions { display:flex; justify-content:center; gap:8px; }
.extension-panel-actions .secondary-button { min-height:36px; padding:6px 12px; font-size:.85rem; }
.interaction-controls { opacity:0; pointer-events:none; transition:opacity .18s ease; }
.show-interaction-controls .interaction-controls { opacity:1; pointer-events:auto; }

.floating-controls { position:fixed; left:50%; bottom:0; z-index:50; display:flex; gap:10px; width:min(1000px,calc(100% - 24px)); padding:10px 12px; border:1px solid rgba(154,191,245,.35); border-bottom:0; border-radius:16px 16px 0 0; background:rgba(5,11,22,.96); box-shadow:0 -8px 30px rgba(0,0,0,.34); transform:translate(-50%,calc(100% - 5px)); opacity:.05; transition:transform .28s ease,opacity .2s ease; }
.floating-controls.is-visible { transform:translate(-50%,0); opacity:1; }
.control-button { flex:1 1 0; min-width:0; min-height:48px; white-space:nowrap; }
.finish-button { flex:.65 1 0; }

.extension-dialog { width:min(560px,calc(100% - 28px)); border:1px solid rgba(148,187,245,.45); border-radius:20px; background:linear-gradient(145deg,#15233a,#070d18); color:#f7f9ff; box-shadow:0 20px 60px rgba(0,0,0,.58); }
.extension-dialog::backdrop { background:rgba(0,0,0,.68); backdrop-filter:blur(3px); }
.extension-form { display:grid; gap:16px; padding:4px; }
.extension-form h2 { margin:0 0 2px; font-size:1.45rem; }
.extension-current-total { padding:10px 12px; border:1px solid rgba(241,194,95,.3); border-radius:12px; background:rgba(142,91,12,.16); color:#f6d88d; font-weight:700; }
.dialog-actions { display:flex; justify-content:flex-end; gap:10px; margin-top:4px; }

.visually-hidden { position:absolute!important; width:1px!important; height:1px!important; padding:0!important; margin:-1px!important; overflow:hidden!important; clip:rect(0,0,0,0)!important; white-space:nowrap!important; border:0!important; }

/* PCで3段をできるだけ1画面に収める */
@media (min-width:901px) {
  .board-screen { padding-bottom:10px; }
  .board-screen .page-header h1 { font-size:clamp(1.5rem,2vw,2.4rem); }
  .board-screen .timer-panel-inner { min-height:clamp(165px,17vh,255px); }
  .board-screen .minutes-display, .board-screen .seconds-display { font-size:clamp(3rem,5.4vw,6.2rem); }
  .board-screen .time-colon { font-size:clamp(2.1rem,3.4vw,4rem); }
  body.board-compact .app-shell { padding-top:10px; padding-bottom:8px; }
  body.board-compact .board-header { margin-bottom:8px; }
  body.board-compact .timer-section { margin-bottom:8px; padding:8px 10px; }
  body.board-compact .section-heading { margin-bottom:5px; }
  body.board-compact .section-heading h2 { font-size:clamp(1.15rem,1.55vw,1.7rem); }
  body.board-compact .timer-panel-inner { min-height:clamp(135px,15.5vh,210px); }
  body.board-compact .timer-title { font-size:clamp(1rem,1.45vw,1.55rem); }
  body.board-compact .minutes-display, body.board-compact .seconds-display { font-size:clamp(2.6rem,4.7vw,5rem); }
  body.board-compact .time-colon { font-size:clamp(1.9rem,3vw,3.4rem); }
  body.board-extra-compact .board-header { margin-bottom:4px; }
  body.board-extra-compact .board-header h1 { font-size:1.35rem; }
  body.board-extra-compact .timer-section { margin-bottom:5px; padding:6px 8px; }
  body.board-extra-compact .timer-panel-inner { min-height:120px; }
  body.board-extra-compact .timer-title { font-size:.95rem; }
  body.board-extra-compact .minutes-display, body.board-extra-compact .seconds-display { font-size:clamp(2.2rem,4.2vw,4.3rem); }
  body.board-extra-compact .time-colon { font-size:2.4rem; }
  body.board-extra-compact .extension-history, body.board-extra-compact .extension-total { font-size:.64rem; }
}

@media (max-width:1100px) and (min-width:701px) {
  .timer-grid { grid-template-columns:repeat(2,minmax(0,1fr)); }
}

@media (max-width:900px) {
  .board-screen { padding-bottom:74px; }
  .timer-grid { grid-template-columns:repeat(2,minmax(0,1fr)); }
  .timer-panel-inner { min-height:250px; }
  .minutes-display, .seconds-display { font-size:clamp(4rem,12vw,7rem); }
  .floating-controls { width:calc(100% - 12px); gap:6px; padding:8px; }
  .control-button { font-size:.82rem; padding:8px 6px; }
}

@media (max-width:700px) {
  .setup-group-header, .timer-setting-row { grid-template-columns:1fr; }
  .duration-fields, .extension-duration-row { grid-template-columns:repeat(2,minmax(0,1fr)); }
}

@media (max-width:560px) {
  .app-shell { padding:10px; }
  .timer-grid { grid-template-columns:1fr; }
  .timer-panel-inner { min-height:300px; }
  .minutes-display, .seconds-display { font-size:clamp(5.2rem,29vw,9rem); }
  .time-colon { font-size:clamp(3.6rem,15vw,5.4rem); }
  .floating-controls { display:grid; grid-template-columns:repeat(2,minmax(0,1fr)); }
  .finish-button { grid-column:span 2; }
  .dialog-actions { display:grid; grid-template-columns:1fr 1fr; }
}

@media (prefers-reduced-motion:reduce) {
  * { scroll-behavior:auto!important; transition:none!important; }
}