:root {
    --bg: #0f1220;
    --bg-soft: #151a2e;
    --panel: #1c2240;
    --card: #101526;
    --text: #e8ecf1;
    --muted: #9aa3b2;
    --primary: #6c9cff;
    --primary-2: #8ad1ff;
    --accent: #ff7aa2;
    --border: rgba(255, 255, 255, 0.08);
    --radius: 14px;
    --shadow: 0 6px 24px rgba(0, 0, 0, 0.35);
    --shadow-soft: 0 4px 16px rgba(0, 0, 0, 0.25);
}

* {
    box-sizing: border-box;
}

html,
body {
    margin: 0;
    padding: 0;
    background: radial-gradient(1200px 600px at 20% -10%, #1b2143 0%, transparent 60%),
        radial-gradient(1000px 800px at 100% 10%, #1a2748 0%, transparent 60%),
        var(--bg);
    color: var(--text);
    font-family: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Noto Sans JP", "Hiragino Kaku Gothic ProN", "Yu Gothic UI", Arial, sans-serif;
    line-height: 1.65;
}

.container {
    max-width: 1080px;
    margin: 0 auto;
    padding: 32px 20px 60px;
}

.page-header {
    padding: 28px 24px;
    background: linear-gradient(135deg, rgba(108, 156, 255, 0.18), rgba(138, 209, 255, 0.12));
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow-soft);
    margin-bottom: 18px;
}

.page-header h1 {
    margin: 0 0 6px;
    font-size: 28px;
    letter-spacing: .4px;
}

.page-header .subtitle {
    margin: 0;
    color: var(--muted);
    font-size: 14px;
}

.page-header .ref {
    margin: 8px 0 0;
}

.page-header .ref a {
    color: #8ad1ff;
    text-decoration: none;
}

.page-header .ref a:hover {
    text-decoration: underline;
}

.card {
    background: var(--bg-soft);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow-soft);
    padding: 16px;
}

/* Tabs */
.tabs {
    display: flex;
    gap: 12px;
    align-items: flex-end;
    border-bottom: 1px solid var(--border);
    margin-bottom: 14px;
    padding: 0 8px;
}

.tab-btn {
    position: relative;
    background: transparent;
    color: var(--muted);
    border: none;
    padding: 12px 10px;
    font-weight: 700;
    letter-spacing: .2px;
    cursor: pointer;
    transition: color .2s ease;
}

.tab-btn:hover {
    color: #c9d4e7;
}

.tab-btn.active {
    color: var(--text);
}

.tab-btn.active::after {
    content: "";
    position: absolute;
    left: 10px;
    right: 10px;
    bottom: -1px;
    height: 3px;
    border-radius: 3px;
    background: linear-gradient(90deg, var(--primary), var(--primary-2));
    box-shadow: 0 2px 8px rgba(108, 156, 255, 0.6);
}

/* Panels: 分割表示の要（これがないと両方表示されます） */
.tab-panel {
    display: none;
}

.tab-panel.active {
    display: block;
}

/* Fieldset */
.fieldset {
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 16px;
    background: linear-gradient(180deg, rgba(255, 255, 255, 0.02), rgba(255, 255, 255, 0.01));
    margin: 14px 0;
}

.fieldset legend {
    padding: 0 6px;
    color: #dbe6ff;
    font-weight: 700;
}

/* Form grid */
.row {
    display: flex;
    gap: 18px;
    flex-wrap: wrap;
}

.col {
    flex: 1 1 280px;
    min-width: 240px;
}

label {
    display: block;
    margin: 8px 0 6px;
    font-weight: 700;
    color: #dbe6ff;
}

input,
select {
    width: 100%;
    padding: 10px 12px;
    border-radius: 10px;
    background: var(--card);
    border: 1px solid var(--border);
    color: var(--text);
    outline: none;
    transition: border-color .2s ease, box-shadow .2s ease, transform .04s ease;
}

input:focus,
select:focus {
    border-color: rgba(108, 156, 255, 0.65);
    box-shadow: 0 0 0 4px rgba(108, 156, 255, 0.15);
}

.hint {
    color: var(--muted);
    font-size: 0.92em;
    margin-top: 6px;
}

.hint ul {
    margin: 6px 0 0;
    padding-left: 18px;
}

.hint li {
    margin: 2px 0;
}

/* Buttons */
.actions {
    margin-top: 10px;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 16px;
    border-radius: 10px;
    border: 1px solid transparent;
    cursor: pointer;
    font-weight: 800;
    letter-spacing: .3px;
    transition: transform .05s ease, filter .2s ease, background .2s ease, box-shadow .2s ease;
}

.btn.primary {
    background: linear-gradient(135deg, var(--primary), var(--primary-2));
    color: #0b1022;
    box-shadow: 0 6px 18px rgba(108, 156, 255, 0.35);
}

.btn.primary:hover {
    filter: brightness(1.06);
}

.btn:active {
    transform: translateY(1px);
}

/* Alerts */
.alert {
    padding: 10px 14px;
    border-radius: 10px;
    margin: 12px 0;
    border: 1px solid var(--border);
    box-shadow: var(--shadow-soft);
}

.alert.error {
    background: rgba(255, 84, 84, 0.12);
    color: #ffaaaa;
}

/* Result table area */
.result {
    margin-top: 18px;
    background: var(--bg-soft);
    border-radius: var(--radius);
    border: 1px solid var(--border);
    padding: 10px 14px;
    box-shadow: var(--shadow-soft);
}

.result table {
    width: 100%;
    border-collapse: collapse;
    overflow: hidden;
    border-radius: 10px;
}

.result th,
.result td {
    border: 1px solid rgba(255, 255, 255, 0.08);
    padding: 10px 12px;
}

.result th {
    background: linear-gradient(180deg, rgba(108, 156, 255, 0.15), rgba(108, 156, 255, 0.05));
    text-align: right;
}

.result td {
    text-align: right;
}

.result tr:nth-child(even) td {
    background: rgba(255, 255, 255, 0.02);
}

/* Small screens */
@media (max-width: 640px) {
    .container {
        padding: 20px 14px 40px;
    }

    .page-header {
        padding: 20px 16px;
    }

    .page-header h1 {
        font-size: 22px;
    }

    .col {
        min-width: 100%;
    }
}