/* -------------------------------------------------------
   main.css — Hot Tub Maintenance Site
   Light theme, mobile-first
------------------------------------------------------- */

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

:root {
    --bg-base:       #f4f6f9;
    --bg-card:       #ffffff;
    --bg-card-alt:   #eef1f5;
    --accent:        #0077cc;
    --accent-dim:    #005fa3;
    --text-primary:  #1c1c2e;
    --text-muted:    #6b6b80;
    --border:        #dde1ea;
    --ok:            #4caf50;
    --warn:          #ff9800;
    --danger:        #e53935;
    --radius:        8px;
    --shadow:        0 2px 12px rgba(0,0,0,0.08);
}

html {
    font-size: 16px;
}

body {
    background-color: var(--bg-base);
    color: var(--text-primary);
    font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
    line-height: 1.6;
    min-height: 100vh;
}

a {
    color: var(--accent);
    text-decoration: none;
}

a:hover {
    color: var(--accent-dim);
    text-decoration: underline;
}

/* === Layout === */
.site-header {
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
    padding: 1rem 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.site-header h1 {
    font-size: 1.3rem;
    color: var(--accent);
    letter-spacing: 0.03em;
}

.site-header h1 span {
    color: var(--text-muted);
    font-weight: 400;
    font-size: 0.9rem;
}

nav {
    display: flex;
    gap: 0.5rem;
    flex-wrap: wrap;
}

nav a {
    background: var(--bg-card-alt);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    color: var(--text-primary);
    padding: 0.4rem 0.85rem;
    font-size: 0.85rem;
    transition: background 0.15s, border-color 0.15s;
}

nav a:hover, nav a.active {
    background: var(--accent);
    border-color: var(--accent);
    color: #fff;
    text-decoration: none;
}

.container {
    max-width: 960px;
    margin: 0 auto;
    padding: 1.5rem 1rem;
}

/* === Cards === */
.card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 1.25rem;
    margin-bottom: 1.25rem;
}

.card h2 {
    font-size: 1rem;
    color: var(--accent);
    margin-bottom: 1rem;
    border-bottom: 1px solid var(--border);
    padding-bottom: 0.5rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* === Status Badges === */
.badge {
    display: inline-block;
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 700;
    padding: 0.15rem 0.5rem;
    letter-spacing: 0.04em;
    text-transform: uppercase;
}

.badge-ok      { background: var(--ok);     color: #fff; }
.badge-warn    { background: var(--warn);   color: #000; }
.badge-danger  { background: var(--danger); color: #fff; }
.badge-unknown { background: var(--border); color: var(--text-muted); }

/* === Reading Grid === */
.readings-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: 0.75rem;
}

.reading-item {
    background: var(--bg-card-alt);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 0.85rem;
    text-align: center;
}

.reading-item .label {
    font-size: 0.72rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.06em;
    margin-bottom: 0.3rem;
}

.reading-item .value {
    font-size: 1.6rem;
    font-weight: 700;
    line-height: 1.1;
}

.reading-item .unit {
    font-size: 0.75rem;
    color: var(--text-muted);
}

.reading-item .status {
    margin-top: 0.4rem;
}

/* === Alert Bars === */
.alert {
    border-left: 4px solid;
    border-radius: var(--radius);
    padding: 0.75rem 1rem;
    margin-bottom: 0.75rem;
    font-size: 0.9rem;
}

.alert-ok     { border-color: var(--ok);     background: rgba(76,175,80,0.1); }
.alert-warn   { border-color: var(--warn);   background: rgba(255,152,0,0.1); }
.alert-danger { border-color: var(--danger); background: rgba(244,67,54,0.1); }

/* === Quick Actions === */
.actions-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 0.75rem;
}

.btn {
    display: block;
    background: var(--bg-card-alt);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    color: var(--text-primary);
    cursor: pointer;
    font-size: 0.95rem;
    padding: 0.85rem 1rem;
    text-align: center;
    transition: background 0.15s, border-color 0.15s, color 0.15s;
    width: 100%;
    text-decoration: none;
}

.btn:hover {
    background: var(--accent);
    border-color: var(--accent);
    color: #fff;
    text-decoration: none;
}

.btn-primary {
    background: var(--accent);
    border-color: var(--accent);
    color: #fff;
    font-weight: 600;
}

.btn-primary:hover {
    background: var(--accent-dim);
    border-color: var(--accent-dim);
    color: #fff;
}

/* === Forms === */
.form-group {
    margin-bottom: 1.1rem;
}

.form-group label {
    display: block;
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-bottom: 0.35rem;
    text-transform: uppercase;
    letter-spacing: 0.04em;
}

.form-group input[type="text"],
.form-group input[type="number"],
.form-group input[type="date"],
.form-group select,
.form-group textarea {
    background: var(--bg-base);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    color: var(--text-primary);
    font-family: inherit;
    font-size: 1rem;
    padding: 0.65rem 0.85rem;
    width: 100%;
    transition: border-color 0.15s;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    border-color: var(--accent);
    outline: none;
}

.form-group textarea {
    min-height: 90px;
    resize: vertical;
}

.form-group .hint {
    font-size: 0.78rem;
    color: var(--text-muted);
    margin-top: 0.25rem;
}

.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: 0.75rem;
}

/* === Tables === */
.table-wrap {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
}

table {
    border-collapse: collapse;
    width: 100%;
    font-size: 0.9rem;
}

thead th {
    background: var(--bg-card-alt);
    border-bottom: 2px solid var(--border);
    color: var(--text-muted);
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.05em;
    padding: 0.6rem 0.75rem;
    text-align: left;
    text-transform: uppercase;
    white-space: nowrap;
}

tbody tr {
    border-bottom: 1px solid var(--border);
}

tbody tr:hover {
    background: var(--bg-card-alt);
}

tbody td {
    padding: 0.6rem 0.75rem;
    vertical-align: middle;
    white-space: nowrap;
}

/* === Flash Messages === */
.flash {
    border-radius: var(--radius);
    font-size: 0.9rem;
    margin-bottom: 1rem;
    padding: 0.75rem 1rem;
}

.flash-ok      { background: rgba(76,175,80,0.15);  border: 1px solid var(--ok);     color: var(--ok); }
.flash-error   { background: rgba(244,67,54,0.15);  border: 1px solid var(--danger); color: var(--danger); }

/* === Chart === */
.chart-wrap {
    position: relative;
    height: 220px;
}

/* === Footer === */
.site-footer {
    border-top: 1px solid var(--border);
    color: var(--text-muted);
    font-size: 0.78rem;
    margin-top: 2rem;
    padding: 1rem;
    text-align: center;
}

/* === Utility === */
.text-muted    { color: var(--text-muted); }
.td-empty      { color: var(--text-muted); text-align: center; }
.td-wrap       { white-space: normal; }
.td-notes      { white-space: normal; max-width: 200px; }
.card-subtitle { font-size: 0.75rem; font-weight: 400; color: var(--text-muted); text-transform: none; letter-spacing: 0; }
.reading-notes { margin-top: 0.85rem; font-size: 0.88rem; color: var(--text-muted); }

/* === Installer (install.php) === */
.text-ok   { color: var(--ok); }
.text-err  { color: var(--danger); }
.install-warn {
    background: var(--warn);
    color: #000;
    padding: 1rem;
    border-radius: var(--radius);
    margin-top: 1.5rem;
    font-weight: bold;
}

/* === Tab Bar (history.php) === */
.tab-bar { display: flex; gap: 0.5rem; margin-bottom: 1rem; }
.tab-bar a {
    background: var(--bg-card-alt);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    color: var(--text-muted);
    padding: 0.4rem 1rem;
    font-size: 0.9rem;
    text-decoration: none;
}
.tab-bar a.active {
    background: var(--accent);
    border-color: var(--accent);
    color: #fff;
    font-weight: 600;
}

/* === Pagination === */
.pagination { display: flex; gap: 0.4rem; flex-wrap: wrap; margin-top: 1rem; }
.pagination a, .pagination span {
    background: var(--bg-card-alt);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    color: var(--text-primary);
    display: inline-block;
    font-size: 0.85rem;
    padding: 0.35rem 0.7rem;
    text-decoration: none;
}
.pagination a:hover  { background: var(--accent); border-color: var(--accent); color: #fff; }
.pagination .current { background: var(--accent); border-color: var(--accent); color: #fff; font-weight: 700; }

/* === Responsive === */
@media (max-width: 480px) {
    .site-header {
        flex-direction: column;
        align-items: flex-start;
    }

    .readings-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .form-row {
        grid-template-columns: 1fr;
    }
}