:root {
	color-scheme: light dark;
	--bg: #f4f5fa;
	--card: #ffffff;
	--text: #1c1d22;
	--muted: #6b6f7b;
	--line: #e3e5ec;
	--accent: #5b8cff;
	--accent-2: #7c4dff;
	--danger: #e5484d;
	--warn: #e5484d;
	--today: #f59e0b;
	--radius: 14px;
}

@media (prefers-color-scheme: dark) {
	:root {
		--bg: #111216;
		--card: #1b1c22;
		--text: #eceef4;
		--muted: #9a9eab;
		--line: #2a2c34;
		--accent: #7aa2ff;
	}
}

* {
	box-sizing: border-box;
}

html,
body {
	margin: 0;
	background: var(--bg);
	color: var(--text);
	font-family: system-ui, -apple-system, "Segoe UI", "Hiragino Sans", "Yu Gothic UI", sans-serif;
	-webkit-text-size-adjust: 100%;
}

[hidden] {
	display: none !important;
}

button,
input,
textarea {
	font: inherit;
	color: inherit;
}

input,
textarea {
	width: 100%;
	padding: 10px 12px;
	border: 1px solid var(--line);
	border-radius: 10px;
	background: var(--card);
	font-size: 16px; /* iOS のズーム防止 */
}

input:focus,
textarea:focus {
	outline: 2px solid var(--accent);
	outline-offset: -1px;
}

button {
	padding: 9px 16px;
	border: 1px solid var(--line);
	border-radius: 10px;
	background: var(--card);
	cursor: pointer;
	white-space: nowrap;
}

button.primary {
	background: linear-gradient(135deg, var(--accent), var(--accent-2));
	border: none;
	color: #fff;
	font-weight: 600;
}

button.danger {
	color: var(--danger);
}

.icon-btn {
	width: 38px;
	height: 38px;
	padding: 0;
	border: none;
	background: transparent;
	font-size: 18px;
	color: var(--muted);
}

/* ---------- setup ---------- */
.setup {
	max-width: 380px;
	margin: 0 auto;
	padding: 80px 16px calc(40px + env(safe-area-inset-bottom));
	text-align: center;
}

.setup img {
	border-radius: 18px;
}

.setup p {
	color: var(--muted);
	line-height: 1.6;
}

.setup form {
	display: grid;
	gap: 10px;
}

.error {
	color: var(--danger);
	margin: 0;
}

/* ---------- app ---------- */
.app {
	max-width: 640px;
	margin: 0 auto;
	padding: env(safe-area-inset-top) 16px calc(40px + env(safe-area-inset-bottom));
}

.topbar {
	display: flex;
	align-items: center;
	gap: 4px;
	padding: 14px 0 10px;
	position: sticky;
	top: 0;
	background: var(--bg);
	z-index: 2;
}

.topbar h1 {
	font-size: 24px;
	margin: 0;
	flex: 1;
}

.sync-state {
	width: 8px;
	height: 8px;
	border-radius: 50%;
	background: #22c55e;
	margin-right: 6px;
}

.sync-state.busy {
	background: var(--today);
}

.sync-state.error {
	background: var(--danger);
}

.add-form {
	display: grid;
	gap: 8px;
	background: var(--card);
	border: 1px solid var(--line);
	border-radius: var(--radius);
	padding: 12px;
	margin-bottom: 18px;
}

.add-row {
	display: flex;
	gap: 8px;
}

.add-row input {
	flex: 1;
	min-width: 0;
}

.chips {
	display: flex;
	gap: 6px;
	flex-wrap: wrap;
}

.chips button {
	padding: 4px 10px;
	font-size: 13px;
	border-radius: 999px;
	color: var(--muted);
}

/* ---------- list ---------- */
.group {
	margin-bottom: 18px;
}

.group > h2 {
	font-size: 13px;
	font-weight: 600;
	color: var(--muted);
	margin: 0 4px 6px;
	display: flex;
	gap: 6px;
	cursor: pointer;
	user-select: none;
}

.group.overdue > h2 {
	color: var(--warn);
}

.group.today > h2 {
	color: var(--today);
}

.group ul {
	list-style: none;
	margin: 0;
	padding: 0;
	background: var(--card);
	border: 1px solid var(--line);
	border-radius: var(--radius);
	overflow: hidden;
}

.group.collapsed ul {
	display: none;
}

.item {
	display: flex;
	align-items: flex-start;
	gap: 12px;
	padding: 12px 14px;
	border-top: 1px solid var(--line);
	cursor: pointer;
}

.item:first-child {
	border-top: none;
}

.check {
	flex: none;
	width: 22px;
	height: 22px;
	margin-top: 1px;
	border-radius: 50%;
	border: 2px solid var(--muted);
	background: transparent;
	padding: 0;
	display: grid;
	place-items: center;
	color: #fff;
	font-size: 13px;
}

.item.done .check {
	background: var(--accent);
	border-color: var(--accent);
}

.item-body {
	flex: 1;
	min-width: 0;
}

.item-title {
	overflow-wrap: anywhere;
	line-height: 1.4;
}

.item.done .item-title {
	color: var(--muted);
	text-decoration: line-through;
}

.item-meta {
	font-size: 13px;
	color: var(--muted);
	margin-top: 2px;
	overflow: hidden;
	text-overflow: ellipsis;
	white-space: nowrap;
}

.item-meta .due.overdue {
	color: var(--warn);
	font-weight: 600;
}

.item-meta .due.today {
	color: var(--today);
}

.empty {
	text-align: center;
	color: var(--muted);
	margin-top: 40px;
}

/* ---------- dialog ---------- */
dialog {
	width: min(480px, calc(100vw - 32px));
	border: none;
	border-radius: 18px;
	padding: 20px;
	background: var(--card);
	color: var(--text);
}

dialog::backdrop {
	background: rgb(0 0 0 / 0.4);
}

dialog h2 {
	margin: 0 0 12px;
	font-size: 18px;
}

dialog form {
	display: grid;
	gap: 12px;
}

dialog label {
	display: grid;
	gap: 4px;
	font-size: 13px;
	color: var(--muted);
}

dialog label input,
dialog label textarea {
	color: var(--text);
}

.dialog-actions {
	display: flex;
	gap: 8px;
	margin-top: 4px;
}

.spacer {
	flex: 1;
}