/* ===================================================
   Reset & Base
=================================================== */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    --color-primary:    #4f46e5;
    --color-primary-h:  #4338ca;
    --color-bg:         #f8fafc;
    --color-surface:    #ffffff;
    --color-text:       #1e293b;
    --color-muted:      #64748b;
    --color-border:     #e2e8f0;
    --font-sans:        'Segoe UI', system-ui, -apple-system, sans-serif;
    --radius:           0.5rem;
    --shadow:           0 1px 3px rgb(0 0 0 / .1);
}

body {
    font-family: var(--font-sans);
    background: var(--color-bg);
    color: var(--color-text);
    line-height: 1.6;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* ===================================================
   Layout
=================================================== */
.container {
    width: 100%;
    max-width: 1200px;
    margin-inline: auto;
    padding-inline: 1.5rem;
}

.main-content {
    flex: 1;
    padding-block: 2.5rem;
}

/* ===================================================
   Header & Nav
=================================================== */
.site-header {
    background: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 100;
}

.site-header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 4rem;
}

.logo {
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--color-primary);
    text-decoration: none;
}

.main-nav ul {
    list-style: none;
    display: flex;
    gap: 1.5rem;
}

.main-nav a {
    color: var(--color-muted);
    text-decoration: none;
    font-size: 0.95rem;
    transition: color .2s;
}

.main-nav a:hover {
    color: var(--color-primary);
}

.main-nav a.active {
    color: var(--color-primary);
    font-weight: 600;
}

/* ===================================================
   Footer
=================================================== */
.site-footer {
    background: var(--color-surface);
    border-top: 1px solid var(--color-border);
    padding-block: 1.25rem;
    text-align: center;
    color: var(--color-muted);
    font-size: 0.875rem;
}

.site-footer p + p {
    margin-top: .35rem;
}

.site-footer .license-note a {
    color: var(--color-primary);
    text-decoration: none;
}

.site-footer .license-note a:hover {
    text-decoration: underline;
}

/* ===================================================
   Buttons
=================================================== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: .5rem;
    padding: .625rem 1.25rem;
    border-radius: var(--radius);
    font-size: .9375rem;
    font-weight: 500;
    cursor: pointer;
    text-decoration: none;
    border: none;
    transition: background .2s, transform .1s;
}

.btn:active { transform: scale(0.98); }

.btn-primary {
    background: var(--color-primary);
    color: #fff;
}

.btn-primary:hover {
    background: var(--color-primary-h);
}

/* ===================================================
   Hero
=================================================== */
.hero {
    text-align: center;
    padding-block: 4rem;
}

.hero h1 {
    font-size: clamp(1.75rem, 4vw, 2.75rem);
    margin-bottom: 1rem;
}

.hero p {
    color: var(--color-muted);
    max-width: 560px;
    margin-inline: auto;
    margin-bottom: 2rem;
}

/* ===================================================
   Generic page section
=================================================== */
.page-section h1 {
    font-size: 2rem;
    margin-bottom: 1rem;
}

.page-section ul {
    margin-left: 1.5rem;
    margin-top: .75rem;
    color: var(--color-muted);
    line-height: 2;
}

.text-muted {
    color: var(--color-muted);
}

.mt-3 {
    margin-top: 1rem;
}

.mt-4 {
    margin-top: 1.5rem;
}

.card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.card-header {
    border-bottom: 1px solid var(--color-border);
    padding: 1rem 1.25rem;
}

.card-header h2 {
    font-size: 1.1rem;
}

.card-body {
    padding: 1rem 1.25rem;
}

.wb-controls {
    display: grid;
    grid-template-columns: 1.4fr repeat(3, minmax(120px, 180px));
    gap: .75rem;
}

.wb-controls input,
.wb-controls select {
    width: 100%;
    padding: .6rem .8rem;
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    font-size: .9rem;
    background: #fff;
}

.wb-stats {
    display: grid;
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: .75rem;
}

.wb-stat-card {
    background: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    padding: .9rem;
}

.wb-stat-card span {
    display: block;
    color: var(--color-muted);
    font-size: .8rem;
    margin-bottom: .4rem;
}

.wb-stat-card strong {
    font-size: 1.2rem;
}

.wb-table-wrap {
    overflow-x: auto;
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    background: #fff;
}

.wb-table {
    width: 100%;
    border-collapse: collapse;
    font-size: .88rem;
    min-width: 1160px;
}

.wb-table th,
.wb-table td {
    padding: .65rem .75rem;
    border-bottom: 1px solid var(--color-border);
    text-align: left;
    white-space: nowrap;
}

.wb-table th {
    font-size: .76rem;
    text-transform: uppercase;
    letter-spacing: .04em;
    color: var(--color-muted);
}

.wb-table tbody tr:hover {
    background: #f8fafc;
}

.wb-pagination {
    display: flex;
    align-items: center;
    gap: .75rem;
}

#bill-page-info {
    font-size: .9rem;
    color: var(--color-muted);
}

.wb-chart-legend {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    color: var(--color-muted);
    font-size: .85rem;
}

.wb-chart-legend label {
    display: inline-flex;
    align-items: center;
    gap: .35rem;
    cursor: pointer;
    user-select: none;
}

.wb-chart-legend input[type="checkbox"] {
    accent-color: var(--color-primary);
}

.wb-yoy {
    display: grid;
    gap: .6rem;
}

.wb-yoy-title {
    font-weight: 700;
    color: var(--color-text);
}

.wb-yoy-grid {
    display: grid;
    gap: .75rem;
    grid-template-columns: repeat(2, minmax(0, 1fr));
}

.wb-yoy-grid span {
    display: block;
    font-size: .82rem;
    color: var(--color-muted);
    margin-bottom: .15rem;
}

.wb-yoy-grid strong {
    font-size: .95rem;
}

.wb-yoy-note {
    margin: 0;
}

.wb-yoy-up {
    color: #b91c1c;
}

.wb-yoy-down {
    color: #166534;
}

.wb-yoy-flat {
    color: var(--color-text);
}

.contact-form {
    background: #fff;
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    padding: 1rem;
}

.form-row {
    display: flex;
    flex-direction: column;
    gap: .35rem;
    margin-bottom: .9rem;
}

.form-row label {
    font-size: .9rem;
    color: var(--color-text);
    font-weight: 600;
}

.form-row input,
.form-row textarea {
    width: 100%;
    padding: .65rem .75rem;
    border: 1px solid var(--color-border);
    border-radius: var(--radius);
    font-size: .95rem;
}

.alert-success,
.alert-danger {
    padding: .75rem 1rem;
    border-radius: var(--radius);
}

.alert-success {
    background: #dcfce7;
    border: 1px solid #86efac;
    color: #166534;
}

.alert-danger {
    background: #fee2e2;
    border: 1px solid #fca5a5;
    color: #991b1b;
}

.dot {
    width: .6rem;
    height: .6rem;
    border-radius: 999px;
    display: inline-block;
}

.dot-blue { background: #2563eb; }
.dot-cyan { background: #06b6d4; }
.dot-green { background: #16a34a; }
.dot-red { background: #dc2626; }
.dot-lime { background: #84cc16; }
.dot-orange { background: #ea580c; }

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

    .wb-stats {
        grid-template-columns: 1fr 1fr;
    }

    .wb-yoy-grid {
        grid-template-columns: 1fr;
    }
}