:root {
    color-scheme: light;
    --c-bg-main: #f4f6fa;
    --c-bg-card: #ffffff;
    --c-text-main: #17243b;
    --c-text-sub: #52617a;
    --c-border: #dbe2ed;
    --c-accent: #2459c4;
    --c-primary: var(--c-accent);
    --c-danger: #b42336;
    --ui-radius: 12px;
    --ui-shadow: 0 4px 20px #17243b06;
}
[data-theme="dark"] {
    color-scheme: dark;
    --c-bg-main: #101827;
    --c-bg-card: #192438;
    --c-text-main: #edf2fb;
    --c-text-sub: #a7b5cb;
    --c-border: #35435a;
    --c-accent: #96b9ff;
    --c-danger: #ff9cab;
    --ui-shadow: none;
}
* { box-sizing: border-box; }
body {
    margin: 0;
    font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "Noto Sans JP", sans-serif;
    line-height: 1.6;
    background: var(--c-bg-main);
    color: var(--c-text-main);
}
a { color: var(--c-accent); text-underline-offset: .2em; }
button, input, select, textarea { font: inherit; }
button { cursor: pointer; }
button:disabled { cursor: default; opacity: .6; }
:focus-visible { outline: 3px solid var(--c-accent); outline-offset: 3px; }
[hidden], .hidden { display: none !important; }
.ui-header {
    flex: 0 0 auto;
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 12px 20px;
    padding: 12px clamp(16px, 3vw, 40px);
    min-height: 64px;
    border-bottom: 1px solid var(--c-border);
    background: var(--c-bg-card);
}
.ui-brand { font-weight: 800; text-decoration: none; letter-spacing: -.02em; }
.ui-header-title { color: var(--c-text-sub); font-size: .875rem; }
.ui-nav { margin-left: auto; display: flex; align-items: center; gap: 16px; font-size: .875rem; }
.ui-nav a { text-decoration: none; }
.ui-nav a:hover { text-decoration: underline; }
.ui-theme-button, .theme-toggle-btn {
    border: 1px solid var(--c-border);
    background: var(--c-bg-main);
    color: var(--c-text-main);
    border-radius: 8px;
    min-height: 36px;
    min-width: 40px;
    padding: 4px 10px;
    line-height: 1.4;
}
.ui-main { width: min(1120px, 100%); margin: 0 auto; padding: 32px 24px 56px; }
.ui-main.ui-wide { width: min(1440px, 100%); }
.ui-heading { margin-bottom: 28px; }
.ui-eyebrow { margin: 0 0 6px; font-size: .75rem; letter-spacing: .12em; text-transform: uppercase; font-weight: 750; color: var(--c-accent); }
.ui-heading h1 { font-size: clamp(1.5rem, 3vw, 2rem); line-height: 1.35; letter-spacing: -.035em; margin: 0 0 10px; }
.ui-description, .ui-note { color: var(--c-text-sub); margin: 0; font-size: .9375rem; }
.ui-note { margin-top: 12px; }
.ui-panel, .card {
    border: 1px solid var(--c-border);
    background: var(--c-bg-card);
    border-radius: var(--ui-radius);
    padding: 24px;
    box-shadow: var(--ui-shadow);
    min-width: 0;
}
.ui-panel + .ui-panel, .card + .card { margin-top: 20px; }
.ui-panel h2, .card h2 { font-size: 1.05rem; margin: 0 0 16px; }
.ui-stack { display: grid; gap: 20px; }
.ui-stack > .ui-panel, .ui-row > .ui-panel { margin-top: 0; }
.ui-row { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 20px; }
.ui-actions { display: flex; gap: 10px; align-items: center; flex-wrap: wrap; }
.ui-between { display: flex; gap: 12px; align-items: center; justify-content: space-between; flex-wrap: wrap; }
.ui-main label, .ui-dialog label { display: block; font-size: .875rem; font-weight: 650; margin-bottom: 8px; }
.ui-main :where(input[type="text"], input[type="search"], input[type="number"], input[type="url"], select, textarea),
.ui-dialog :where(input, select, textarea) {
    width: 100%;
    min-width: 0;
    padding: 11px 12px;
    border: 1px solid var(--c-border);
    border-radius: 8px;
    background: var(--c-bg-main);
    color: var(--c-text-main);
    font-size: 1rem;
}
.ui-main textarea { resize: vertical; min-height: 180px; line-height: 1.65; }
.ui-main input:focus, .ui-main select:focus, .ui-main textarea:focus { border-color: var(--c-accent); }
.ui-button, .btn-primary, .btn-copy, .action-btn, .reset-btn, .btn-small, .btn-icon, .btn-cancel, .btn-danger {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 10px 16px;
    border: 1px solid var(--c-border);
    border-radius: 8px;
    background: var(--c-bg-card);
    color: var(--c-text-main);
    font-size: .9375rem;
    font-weight: 650;
    text-decoration: none;
    line-height: 1.5;
}
.ui-button:hover, .btn-copy:hover, .reset-btn:hover, .btn-small:hover, .btn-icon:hover, .btn-cancel:hover { background: var(--c-bg-main); }
.ui-button-primary, .btn-primary, .action-btn { color: #fff; background: #2459c4; border-color: #2459c4; }
.ui-button-primary:hover, .btn-primary:hover, .action-btn:hover { background: #1947a4; }
.btn-danger { background: #b42336; border-color: #b42336; color: #fff; }
.ui-status { margin-top: 12px; color: var(--c-text-sub); font-size: .875rem; overflow-wrap: anywhere; }
.ui-error, .error { color: var(--c-danger); }
.ui-dialog {
    border: 1px solid var(--c-border);
    border-radius: var(--ui-radius);
    width: min(440px, calc(100% - 32px));
    padding: 24px;
    background: var(--c-bg-card);
    color: var(--c-text-main);
}
.ui-dialog::backdrop { background: #08142699; }
.ui-dialog h2 { margin: 0 0 20px; font-size: 1.2rem; }
.ui-dialog input { margin-bottom: 16px; }
.ui-footer { color: var(--c-text-sub); font-size: .8125rem; margin-top: 24px; }
@media (max-width: 640px) {
    .ui-header { gap: 8px 12px; padding: 10px 16px; }
    .ui-header-title { display: none; }
    .ui-nav { gap: 12px; }
    .ui-main { padding: 24px 16px 40px; }
    .ui-panel, .card { padding: 18px; }
    .ui-row { grid-template-columns: minmax(0, 1fr); }
}
@media (prefers-reduced-motion: reduce) { *, *::before, *::after { scroll-behavior: auto !important; transition: none !important; } }