:root {
    --bg-top: #eaf4ff;
    --bg-bottom: #dbeafe;
    --surface: #ffffff;
    --surface-alt: #f3f8ff;
    --primary: #0ea5e9;
    --primary-dark: #2563eb;
    --primary-soft: #e0f2fe;
    --text: #1e293b;
    --muted: #64748b;
    --border: #dbe7f5;
    --danger: #dc2626;
    --danger-dark: #b91c1c;
    --success: #16a34a;
    --radius: 16px;
    --radius-sm: 10px;
    --shadow: 0 4px 20px rgba(37, 99, 235, 0.08), 0 1px 3px rgba(15, 23, 42, 0.06);
    --btn-shadow: 0 2px 8px rgba(37, 99, 235, 0.25);
    --btn-shadow-hover: 0 4px 14px rgba(37, 99, 235, 0.3);
    --card-hover-shadow: 0 8px 24px rgba(37, 99, 235, 0.15);
    --focus-ring: 0 0 0 3px rgba(14, 165, 233, 0.25);
    --row-hover: #eef6ff;
    --admin-link: #f97316;
    --admin-link-hover: #c2410c;
}

/* Admin pages (<body class="admin">) use an orange theme to stand apart from the public pages */
body.admin {
    --bg-top: #fff7ed;
    --bg-bottom: #ffedd5;
    --surface-alt: #fffaf5;
    --primary: #f97316;
    --primary-dark: #c2410c;
    --primary-soft: #ffedd5;
    --border: #fde2c4;
    --shadow: 0 4px 20px rgba(234, 88, 12, 0.08), 0 1px 3px rgba(15, 23, 42, 0.06);
    --btn-shadow: 0 2px 8px rgba(234, 88, 12, 0.25);
    --btn-shadow-hover: 0 4px 14px rgba(234, 88, 12, 0.3);
    --card-hover-shadow: 0 8px 24px rgba(234, 88, 12, 0.15);
    --focus-ring: 0 0 0 3px rgba(249, 115, 22, 0.25);
    --row-hover: #fff1e3;
}

html:has(body.admin) {
    background: #ffedd5;
}

* {
    box-sizing: border-box;
}

html {
    background: var(--bg-bottom);
}

body {
    font-family: 'Sarabun', system-ui, sans-serif;
    font-size: 16px;
    line-height: 1.6;
    max-width: 880px;
    margin: 0 auto;
    padding: 40px 16px 64px;
    color: var(--text);
    background: linear-gradient(180deg, var(--bg-top) 0%, var(--bg-bottom) 100%) fixed;
    min-height: 100vh;
}

h1 {
    font-size: 1.9rem;
    font-weight: 700;
    margin: 0 0 20px;
    padding-bottom: 12px;
    color: var(--primary-dark);
    position: relative;
}

h1::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: 0;
    width: 64px;
    height: 4px;
    border-radius: 2px;
    background: linear-gradient(90deg, var(--primary), var(--primary-dark));
}

h2 {
    font-size: 1.3rem;
    font-weight: 600;
    margin: 32px 0 12px;
    color: var(--text);
}

a {
    color: var(--primary-dark);
}

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

code {
    background: var(--primary-soft);
    padding: 1px 6px;
    border-radius: 6px;
    font-size: 0.9em;
}

/* Navigation */

nav {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    padding: 6px;
    margin-bottom: 28px;
    background: var(--surface);
    border-radius: 999px;
    box-shadow: var(--shadow);
}

nav a {
    padding: 6px 16px;
    border-radius: 999px;
    color: var(--muted);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.95rem;
    transition: background 0.15s, color 0.15s;
}

nav a:hover {
    background: var(--primary-soft);
    color: var(--primary-dark);
}

/* Pushed to the right end of the nav, apart from the regular links */
nav a.nav-admin,
nav form.nav-logout {
    margin-left: auto;
}

nav a.nav-admin {
    background: var(--admin-link);
    color: #fff;
}

nav a.nav-admin:hover {
    background: var(--admin-link-hover);
    color: #fff;
}

/* Logout is a POST form (CSRF-protected) whose button looks like the nav links */
nav form.nav-logout {
    display: block;
    padding: 0;
    margin-bottom: 0;
    background: none;
    box-shadow: none;
    border-radius: 0;
}

nav form.nav-logout button {
    padding: 6px 16px;
    border-radius: 999px;
    background: none;
    box-shadow: none;
    color: var(--danger);
    font-size: 0.95rem;
    transition: background 0.15s, color 0.15s;
}

nav form.nav-logout button:hover {
    transform: none;
    filter: none;
    background: #fee2e2;
    color: var(--danger-dark);
}

/* Segmented switch between report views */
.view-toggle {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 20px;
}

.view-toggle a {
    padding: 8px 18px;
    border-radius: 999px;
    border: 1px solid var(--border);
    background: var(--surface);
    color: var(--muted);
    font-weight: 600;
    text-decoration: none;
}

.view-toggle a:hover {
    background: var(--primary-soft);
    color: var(--primary-dark);
}

.view-toggle a.active {
    background: var(--primary-dark);
    border-color: var(--primary-dark);
    color: #fff;
}

.required-mark {
    color: var(--danger);
    margin-left: 2px;
}

.field-group {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.field-group[hidden] {
    display: none;
}

.form-note {
    color: var(--muted);
    font-size: 0.9rem;
    margin: 0;
}

th a.sort-link {
    color: inherit;
    text-decoration: none;
}

th a.sort-link:hover {
    text-decoration: underline;
}

.sort-indicator {
    font-size: 0.8em;
    margin-left: 4px;
}

.sort-indicator.inactive {
    opacity: 0.35;
}

/* Forms and cards */

form,
.card {
    background: var(--surface);
    padding: 24px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    margin-bottom: 24px;
}

form {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

label {
    font-weight: 600;
    font-size: 0.95rem;
    color: var(--text);
}

.checkbox-label {
    font-weight: normal;
    display: inline-flex;
    align-items: center;
    gap: 6px;
    margin-right: 12px;
}

/* Post-registration classroom QR code (index.php?success=1) and the footer banner below it */
.classroom-qr {
    text-align: center;
}

.classroom-qr img {
    max-width: 100%;
    height: auto;
}

img.bottom-banner {
    display: block;
    width: 100%;
    max-width: 740px;
    height: auto;
    margin: 0 auto 24px;
    border-radius: var(--radius);
}

/* Registration-open poster popup on a visitor's first view of index.php */
dialog.landing-dialog {
    padding: 0;
    border: none;
    border-radius: var(--radius);
    width: min(560px, 92vw);
    max-height: 92vh;
    overflow: auto;
    background: var(--surface);
    box-shadow: var(--shadow);
}

dialog.landing-dialog::backdrop {
    background: rgba(15, 23, 42, 0.6);
}

dialog.landing-dialog img {
    display: block;
    width: 100%;
    height: auto;
}

dialog.landing-dialog .action-row {
    justify-content: center;
    padding: 12px;
}

/* Choice question (includes/student_form.php): caption, then radios / a dropdown, then the
   "อื่นๆ" text box */
.choice-field {
    gap: 6px;
}

.choice-field [hidden] {
    display: none;
}

/* Address panels (includes/student_form.php addressFields()): a borderless <fieldset> per
   residence, so disabling the hidden one stops its fields being posted */
.address-panel {
    border: 0;
    padding: 0;
    margin: 0;
    min-width: 0;
}

.address-panel[hidden],
.address-panel [hidden] {
    display: none;
}

/* Multi-select list (ทราบข่าวจากช่องทางใด): the browser's own <select multiple>, all options visible */
select[multiple] {
    padding: 6px;
}

select[multiple] option {
    padding: 6px 8px;
    border-radius: 6px;
}

input,
textarea,
select {
    width: 100%;
    padding: 10px 12px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    background: var(--surface-alt);
    font: inherit;
    color: var(--text);
    transition: border-color 0.15s, box-shadow 0.15s, background 0.15s;
}

input[type="checkbox"],
input[type="radio"] {
    width: auto;
    accent-color: var(--primary-dark);
}

input[type="range"] {
    padding: 0;
    accent-color: var(--primary-dark);
}

input:focus,
textarea:focus,
select:focus {
    outline: none;
    border-color: var(--primary);
    background: var(--surface);
    box-shadow: var(--focus-ring);
}

button {
    padding: 10px 20px;
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: #fff;
    border: none;
    border-radius: var(--radius-sm);
    font: inherit;
    font-weight: 600;
    cursor: pointer;
    box-shadow: var(--btn-shadow);
    transition: transform 0.15s, box-shadow 0.15s, filter 0.15s;
}

button:hover {
    transform: translateY(-1px);
    box-shadow: var(--btn-shadow-hover);
    filter: brightness(1.05);
}

button:active {
    transform: translateY(0);
}

button.secondary {
    background: var(--surface);
    color: var(--primary-dark);
    border: 1px solid var(--border);
    box-shadow: none;
}

button.secondary:hover {
    background: var(--primary-soft);
}

button.danger {
    background: linear-gradient(135deg, #ef4444, var(--danger-dark));
    box-shadow: 0 2px 8px rgba(220, 38, 38, 0.25);
}

/* Alerts */

.error,
.success,
.notice {
    padding: 12px 16px;
    border-radius: var(--radius-sm);
    border-left: 4px solid;
}

.error {
    color: var(--danger-dark);
    background: #fee2e2;
    border-color: var(--danger);
}

.success {
    color: #166534;
    background: #dcfce7;
    border-color: var(--success);
}

.notice {
    color: #92400e;
    background: #fef3c7;
    border-color: #f59e0b;
}

/* Tables */

.table-wrap {
    overflow-x: auto;
    margin-bottom: 24px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    background: var(--surface);
}

table {
    width: 100%;
    border-collapse: collapse;
    background: var(--surface);
}

.table-wrap table {
    margin-bottom: 0;
}

th,
td {
    text-align: left;
    padding: 10px 14px;
    border-bottom: 1px solid var(--border);
}

th {
    background: var(--primary-soft);
    color: var(--primary-dark);
    font-weight: 600;
    font-size: 0.9rem;
    white-space: nowrap;
}

tbody tr:nth-child(even) {
    background: var(--surface-alt);
}

tbody tr:hover {
    background: var(--row-hover);
}

tbody tr:last-child td {
    border-bottom: none;
}

table form {
    padding: 0;
    margin: 0;
    box-shadow: none;
    background: none;
}

/* Attendance */

.session-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin: 16px 0;
}

.session-box {
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 12px;
    font-size: 0.9rem;
    font-weight: 700;
    color: #fff;
}

.session-box.checked {
    background: linear-gradient(135deg, #22c55e, var(--success));
}

.session-box.missing {
    background: #cbd5e1;
    color: #475569;
}

.session-table {
    background: var(--surface);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    margin-bottom: 24px;
    overflow: hidden;
}

.session-table-header,
.session-row {
    display: grid;
    grid-template-columns: 56px 88px 96px 1fr 88px;
    align-items: center;
    gap: 8px;
    padding: 10px 16px;
}

.session-table-header {
    font-weight: 600;
    font-size: 0.9rem;
    background: var(--primary-soft);
    color: var(--primary-dark);
    border-bottom: 1px solid var(--border);
}

.session-row {
    background: none;
    box-shadow: none;
    border-radius: 0;
    border-bottom: 1px solid var(--border);
    margin-bottom: 0;
}

.session-row:last-child {
    border-bottom: none;
}

.session-cancelled {
    background: #f1f5f9;
    color: var(--muted);
}

.progress {
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--primary-dark);
}

/* Dashboard */

.feature-links {
    display: grid;
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px;
    background: none;
    box-shadow: none;
    padding: 0;
}

.feature-links a {
    display: block;
    padding: 20px;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    color: var(--text);
    font-weight: 600;
    text-decoration: none;
    transition: transform 0.15s, border-color 0.15s, box-shadow 0.15s;
}

.feature-links a:hover {
    transform: translateY(-2px);
    border-color: var(--primary);
    color: var(--primary-dark);
    box-shadow: var(--card-hover-shadow);
}

/* Small screens */

@media (max-width: 600px) {
    body {
        padding-top: 24px;
    }

    h1 {
        font-size: 1.5rem;
    }

    nav {
        border-radius: var(--radius);
    }

    form,
    .card {
        padding: 18px;
    }

    .session-table-header {
        display: none;
    }

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

.feature-links p {
    grid-column: 1 / -1;
    margin: 0;
    padding: 20px;
    background: var(--surface);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

/* Dashboard is 2 columns, but 1 on phones so the Thai labels aren't squeezed */
@media (max-width: 480px) {
    .feature-links {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .feature-links {
        grid-template-columns: 1fr;
    }
}

/* Compact forms that sit inline (table cells, approval actions) */

.action-row {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
}

form.inline-form {
    display: inline-flex;
    flex-direction: row;
    flex-wrap: wrap;
    align-items: center;
    gap: 8px;
    padding: 0;
    margin: 0;
    background: none;
    box-shadow: none;
}

form.inline-form input[type="text"] {
    width: auto;
    min-width: 160px;
}