:root {
    --color-bg: #ffffff;
    --color-surface: #f5f5f5;
    --color-border: #e0e0e0;
    --color-text: #1a1a1a;
    --color-text-sub: #6b6b6b;
    --radius: 16px;
    --radius-sm: 12px;
    --max-w: 1160px;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: 'Inter', 'Noto Sans JP', sans-serif;
    font-size: 16px;
    color: var(--color-text);
    background: linear-gradient(180deg, #ffffff 0%, #f9f9f9 100%);
    line-height: 1.6;
}

.container {
    width: min(var(--max-w), calc(100% - 40px));
    margin: 0 auto;
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 60;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(8px);
    border-bottom: 2px solid var(--color-text);
}

.header-inner {
    min-height: 56px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.header-title {
    margin: 0;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-size: 1rem;
    font-weight: 800;
}

.header-title svg {
    width: 20px;
    height: 20px;
}

.home-link {
    font-size: 0.8125rem;
    font-weight: 700;
    color: var(--color-text-sub);
    text-decoration: none;
}

.home-link:hover {
    color: var(--color-text);
}

.hero {
    padding: 46px 0 18px;
}

.hero h2 {
    margin: 0;
    font-size: clamp(1.45rem, 2.2vw, 2.1rem);
    line-height: 1.3;
    letter-spacing: -0.02em;
}

.hero p {
    margin: 10px 0 0;
    color: var(--color-text-sub);
}

.section {
    padding: 16px 0 50px;
}

.app-grid {
    display: grid;
    grid-template-columns: minmax(290px, 0.95fr) minmax(450px, 1.3fr);
    gap: 18px;
    align-items: start;
}

.panel {
    border: 3px solid var(--color-text);
    border-radius: var(--radius);
    box-shadow: 5px 5px 0 var(--color-text);
    background: #fff;
    padding: 16px;
}

.field-label {
    display: block;
    font-size: 0.8125rem;
    font-weight: 800;
    margin-bottom: 6px;
}

.form-input {
    width: 100%;
    border: 2px solid var(--color-border);
    border-radius: var(--radius-sm);
    background: #fff;
    color: var(--color-text);
    padding: 10px 12px;
    font-size: 0.9rem;
    font-family: inherit;
    transition: border-color 0.12s ease, box-shadow 0.12s ease;
}

.form-input:focus {
    outline: none;
    border-color: var(--color-text);
    box-shadow: 3px 3px 0 var(--color-text);
}

.helper {
    margin: 8px 0 0;
    font-size: 0.75rem;
    color: var(--color-text-sub);
}

.row-actions {
    display: flex;
    gap: 8px;
    margin-top: 12px;
}

.btn {
    border: 2px solid var(--color-text);
    border-radius: var(--radius-sm);
    background: #fff;
    color: var(--color-text);
    box-shadow: 3px 3px 0 var(--color-text);
    padding: 8px 12px;
    font-size: 0.8125rem;
    font-weight: 800;
    cursor: pointer;
    transition: transform 0.1s ease, box-shadow 0.1s ease;
}

.btn:hover {
    transform: translate(-1px, -1px);
    box-shadow: 4px 4px 0 var(--color-text);
}

.btn:active {
    transform: translate(1px, 1px);
    box-shadow: 1px 1px 0 var(--color-text);
}

.chip-row {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-top: 12px;
}

.chip {
    border: 2px solid var(--color-border);
    border-radius: 999px;
    background: #fff;
    color: var(--color-text-sub);
    font-size: 0.74rem;
    font-weight: 800;
    padding: 5px 10px;
    cursor: pointer;
}

.chip:hover {
    border-color: var(--color-text);
    color: var(--color-text);
}

.control-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px;
    margin-top: 14px;
}

.control-item {
    display: grid;
    gap: 4px;
}

.control-item span {
    font-size: 0.72rem;
    font-weight: 800;
    color: var(--color-text-sub);
}

.toggle-item {
    border: 2px dashed var(--color-border);
    border-radius: 10px;
    padding: 8px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.status-text {
    margin-top: 12px;
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--color-text-sub);
    min-height: 1.2em;
}

.status-text.ok {
    color: #1f7a3b;
}

.status-text.error {
    color: #b42318;
}

.history-panel {
    margin-top: 14px;
    border-top: 2px solid var(--color-border);
    padding-top: 10px;
}

.history-head {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 8px;
}

.history-head h3 {
    margin: 0;
    font-size: 0.82rem;
}

.mini-link {
    border: none;
    background: transparent;
    color: var(--color-text-sub);
    font-size: 0.74rem;
    font-weight: 700;
    cursor: pointer;
}

.mini-link:hover {
    color: var(--color-text);
}

.history-list {
    display: flex;
    flex-wrap: wrap;
    gap: 7px;
}

.history-item {
    border: 1.5px solid var(--color-border);
    border-radius: 999px;
    padding: 3px 8px;
    font-size: 0.72rem;
    font-weight: 700;
    background: #fff;
    cursor: pointer;
}

.history-item:hover {
    border-color: var(--color-text);
}

.best-card {
    border: 2px solid var(--color-text);
    border-radius: 14px;
    background: linear-gradient(160deg, #ffffff 0%, #f6f6f6 100%);
    box-shadow: 3px 3px 0 var(--color-text);
    padding: 12px;
}

.best-badge {
    font-size: 0.66rem;
    font-weight: 800;
    letter-spacing: 0.06em;
    color: var(--color-text-sub);
}

.best-main {
    margin-top: 4px;
}

.best-fraction {
    font-size: clamp(1.35rem, 2vw, 1.8rem);
    font-weight: 800;
    line-height: 1.2;
}

.best-meta {
    margin-top: 2px;
    font-size: 0.78rem;
    color: var(--color-text-sub);
}

.best-actions {
    margin-top: 10px;
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.insight-grid {
    margin-top: 12px;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px;
}

.insight-card {
    border: 2px solid var(--color-border);
    border-radius: 12px;
    background: #fff;
    padding: 10px;
}

.insight-card h3 {
    margin: 0 0 6px;
    font-size: 0.78rem;
}

.mono {
    margin: 0;
    font-family: ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
    font-size: 0.78rem;
    color: var(--color-text-sub);
    word-break: break-all;
}

.result-grid {
    margin-top: 12px;
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(180px, 1fr));
    gap: 10px;
}

.candidate {
    border: 2px solid var(--color-border);
    border-radius: 12px;
    background: #fff;
    padding: 10px;
    cursor: pointer;
    transition: transform 0.12s ease, border-color 0.12s ease;
}

.candidate:hover {
    border-color: var(--color-text);
    transform: translate(-1px, -1px);
}

.candidate-top {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 8px;
}

.candidate-rank {
    font-size: 0.68rem;
    font-weight: 800;
    border: 1.5px solid var(--color-border);
    border-radius: 999px;
    padding: 2px 7px;
    color: var(--color-text-sub);
}

.candidate-frac {
    margin-top: 6px;
    font-size: 1.1rem;
    font-weight: 800;
    line-height: 1.15;
}

.candidate-line {
    font-size: 0.74rem;
    color: var(--color-text-sub);
}

.candidate-line strong {
    color: var(--color-text);
}

@media (max-width: 980px) {
    .app-grid {
        grid-template-columns: 1fr;
    }

    .insight-grid {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 640px) {
    .container {
        width: min(var(--max-w), calc(100% - 26px));
    }

    .row-actions {
        flex-direction: column;
    }

    .btn {
        width: 100%;
    }

    .control-grid {
        grid-template-columns: 1fr;
    }
}

.decimal,
.meta {
    color: var(--color-text-sub);
}

.error,
.score {
    margin-top: 4px;
}

.error {
    color: #345b9b;
}

.score {
    color: #1f7a3b;
    font-weight: 700;
}

.info-card ul {
    margin-top: 8px;
    padding-left: 1.2rem;
}

.info-card li {
    margin-top: 4px;
    font-size: 0.86rem;
}

.info-card p {
    margin-top: 10px;
    font-size: 0.8rem;
    color: var(--color-text-sub);
}

.copy-toast {
    position: fixed;
    left: 50%;
    top: 20px;
    transform: translate(-50%, -16px);
    border: 2px solid var(--color-text);
    background: #fff;
    padding: 8px 14px;
    border-radius: 10px;
    font-size: 0.8rem;
    font-weight: 800;
    box-shadow: 3px 3px 0 var(--color-text);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.16s ease, transform 0.16s ease;
    z-index: 100;
}

.copy-toast.show {
    opacity: 1;
    transform: translate(-50%, 0);
}

@media (max-width: 900px) {
    .app-shell {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 640px) {
    .container {
        width: min(var(--max-w), 100% - 30px);
    }

    .input-row {
        flex-direction: column;
        align-items: stretch;
    }

    .btn {
        width: 100%;
    }

    .config-grid {
        grid-template-columns: 1fr;
    }
}