/* ==========================================================
   Excel Caregiver Training - Design System
   Modern, accessible, beautifully themed.
   ========================================================== */

/* ========== CSS RESET ========== */
*, *::before, *::after { box-sizing: border-box; }
* { margin: 0; padding: 0; }
html { -webkit-text-size-adjust: 100%; -webkit-font-smoothing: antialiased; -moz-osx-font-smoothing: grayscale; }
body { line-height: 1.5; min-height: 100vh; }
img, picture, video, canvas, svg { display: block; max-width: 100%; }
input, button, textarea, select { font: inherit; color: inherit; }
button { cursor: pointer; background: none; border: none; }
a { color: inherit; text-decoration: none; }
ul, ol { list-style: none; }
table { border-collapse: collapse; }

/* ========== DESIGN TOKENS ========== */
:root {
    /* Colors — Light theme (default) */
    --color-bg: #f8fafc;
    --color-bg-elev: #ffffff;
    --color-bg-elev-2: #f1f5f9;
    --color-bg-hover: #f1f5f9;
    --color-surface: #ffffff;
    --color-surface-2: #f8fafc;

    --color-text: #0f172a;
    --color-text-muted: #475569;
    --color-text-dim: #94a3b8;
    --color-text-inverse: #ffffff;

    --color-border: #e2e8f0;
    --color-border-strong: #cbd5e1;
    --color-divider: #f1f5f9;

    --color-primary: #0ea5e9;
    --color-primary-hover: #0284c7;
    --color-primary-soft: #e0f2fe;
    --color-primary-text: #0369a1;

    --color-accent: #22c55e;
    --color-accent-hover: #16a34a;
    --color-accent-soft: #dcfce7;
    --color-accent-text: #15803d;

    --color-warning: #f59e0b;
    --color-warning-hover: #d97706;
    --color-warning-soft: #fef3c7;
    --color-warning-text: #92400e;

    --color-danger: #ef4444;
    --color-danger-hover: #dc2626;
    --color-danger-soft: #fee2e2;
    --color-danger-text: #991b1b;

    --color-info: #6366f1;
    --color-info-hover: #4f46e5;
    --color-info-soft: #e0e7ff;
    --color-info-text: #3730a3;

    /* Shadows */
    --shadow-xs: 0 1px 2px rgba(15, 23, 42, .04);
    --shadow-sm: 0 1px 3px rgba(15, 23, 42, .06), 0 1px 2px rgba(15, 23, 42, .04);
    --shadow-md: 0 4px 6px -1px rgba(15, 23, 42, .08), 0 2px 4px -2px rgba(15, 23, 42, .06);
    --shadow-lg: 0 10px 15px -3px rgba(15, 23, 42, .08), 0 4px 6px -4px rgba(15, 23, 42, .06);
    --shadow-xl: 0 20px 25px -5px rgba(15, 23, 42, .10), 0 8px 10px -6px rgba(15, 23, 42, .08);

    /* Radii */
    --radius-xs: 4px;
    --radius-sm: 6px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-2xl: 20px;
    --radius-full: 9999px;

    /* Spacing */
    --space-1: 4px;
    --space-2: 8px;
    --space-3: 12px;
    --space-4: 16px;
    --space-5: 20px;
    --space-6: 24px;
    --space-8: 32px;
    --space-10: 40px;
    --space-12: 48px;
    --space-16: 64px;

    /* Typography */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-mono: ui-monospace, SFMono-Regular, 'SF Mono', Menlo, Monaco, Consolas, monospace;

    --text-xs: 12px;
    --text-sm: 13px;
    --text-base: 14px;
    --text-md: 15px;
    --text-lg: 17px;
    --text-xl: 20px;
    --text-2xl: 24px;
    --text-3xl: 30px;
    --text-4xl: 36px;
    --text-5xl: 48px;

    --leading-tight: 1.25;
    --leading-snug: 1.375;
    --leading-normal: 1.5;
    --leading-relaxed: 1.625;

    --weight-regular: 400;
    --weight-medium: 500;
    --weight-semi: 600;
    --weight-bold: 700;
    --weight-extra: 800;

    /* Layout */
    --container-max: 1280px;
    --sidebar-width: 260px;
    --sidebar-collapsed: 72px;
    --header-height: 64px;

    /* Transitions */
    --transition-fast: 100ms ease;
    --transition-base: 150ms ease;
    --transition-slow: 250ms ease;
}

[data-theme="dark"] {
    --color-bg: #0a0a14;
    --color-bg-elev: #15172a;
    --color-bg-elev-2: #1d1f3a;
    --color-bg-hover: #1d1f3a;
    --color-surface: #15172a;
    --color-surface-2: #1d1f3a;

    --color-text: #f1f5f9;
    --color-text-muted: #cbd5e1;
    --color-text-dim: #94a3b8;
    --color-text-inverse: #0f172a;

    --color-border: #2a2d4a;
    --color-border-strong: #3a3d5e;
    --color-divider: #1d1f3a;

    --color-primary: #38bdf8;
    --color-primary-hover: #7dd3fc;
    --color-primary-soft: #0c4a6e;
    --color-primary-text: #7dd3fc;

    --color-accent: #4ade80;
    --color-accent-hover: #86efac;
    --color-accent-soft: #14532d;
    --color-accent-text: #86efac;

    --color-warning: #fbbf24;
    --color-warning-soft: #78350f;
    --color-warning-text: #fcd34d;

    --color-danger: #f87171;
    --color-danger-soft: #7f1d1d;
    --color-danger-text: #fca5a5;

    --color-info: #818cf8;
    --color-info-soft: #312e81;
    --color-info-text: #a5b4fc;

    --shadow-xs: 0 1px 2px rgba(0, 0, 0, .3);
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, .4), 0 1px 2px rgba(0, 0, 0, .3);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, .4), 0 2px 4px -2px rgba(0, 0, 0, .3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, .5), 0 4px 6px -4px rgba(0, 0, 0, .4);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, .6), 0 8px 10px -6px rgba(0, 0, 0, .5);
}

/* ========== BASE ========== */
html { font-family: var(--font-sans); font-size: var(--text-base); }
body {
    background: var(--color-bg);
    color: var(--color-text);
    font-family: var(--font-sans);
    font-size: var(--text-base);
    line-height: var(--leading-normal);
    transition: background-color .15s ease, color .15s ease;
}

a { color: var(--color-primary); }
a:hover { color: var(--color-primary-hover); }
strong { font-weight: var(--weight-semi); }

h1, h2, h3, h4, h5, h6 {
    font-weight: var(--weight-semi);
    line-height: var(--leading-tight);
    color: var(--color-text);
}
h1 { font-size: var(--text-3xl); font-weight: var(--weight-bold); }
h2 { font-size: var(--text-2xl); }
h3 { font-size: var(--text-xl); }
h4 { font-size: var(--text-lg); }
h5 { font-size: var(--text-base); }

::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-track { background: var(--color-bg-elev-2); }
::-webkit-scrollbar-thumb { background: var(--color-border-strong); border-radius: 5px; border: 2px solid var(--color-bg-elev-2); }
::-webkit-scrollbar-thumb:hover { background: var(--color-text-dim); }

::selection { background: var(--color-primary); color: white; }

/* ========== LAYOUT ========== */
.container { max-width: var(--container-max); margin: 0 auto; padding: 0 var(--space-6); }

/* ========== BUTTONS ========== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    padding: 10px 16px;
    font-size: var(--text-sm);
    font-weight: var(--weight-semi);
    line-height: 1;
    border-radius: var(--radius-md);
    border: 1px solid transparent;
    cursor: pointer;
    transition: all var(--transition-base);
    white-space: nowrap;
    text-decoration: none;
}
.btn:disabled, .btn.disabled { opacity: .55; cursor: not-allowed; pointer-events: none; }
.btn:focus-visible { outline: 2px solid var(--color-primary); outline-offset: 2px; }

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

.btn-accent { background: var(--color-accent); color: white; border-color: var(--color-accent); }
.btn-accent:hover { background: var(--color-accent-hover); color: white; }

.btn-warning { background: var(--color-warning); color: white; border-color: var(--color-warning); }
.btn-warning:hover { background: var(--color-warning-hover); color: white; }

.btn-danger { background: var(--color-danger); color: white; border-color: var(--color-danger); }
.btn-danger:hover { background: var(--color-danger-hover); color: white; }

.btn-secondary { background: var(--color-bg-elev); color: var(--color-text); border-color: var(--color-border); }
.btn-secondary:hover { background: var(--color-bg-hover); border-color: var(--color-border-strong); }

.btn-ghost { background: transparent; color: var(--color-text); border-color: transparent; }
.btn-ghost:hover { background: var(--color-bg-hover); }

.btn-outline { background: transparent; color: var(--color-primary); border-color: var(--color-primary); }
.btn-outline:hover { background: var(--color-primary); color: white; }

.btn-sm { padding: 6px 12px; font-size: var(--text-xs); border-radius: var(--radius-sm); }
.btn-lg { padding: 14px 22px; font-size: var(--text-md); }
.btn-block { width: 100%; }
.btn-icon { padding: 10px; }

/* ========== FORMS ========== */
.form-group { margin-bottom: var(--space-5); }
.form-row { display: grid; gap: var(--space-4); }
.form-row.cols-2 { grid-template-columns: 1fr 1fr; }
.form-row.cols-3 { grid-template-columns: 1fr 1fr 1fr; }
@media (max-width: 640px) { .form-row.cols-2, .form-row.cols-3 { grid-template-columns: 1fr; } }

.form-label {
    display: block;
    font-size: var(--text-sm);
    font-weight: var(--weight-medium);
    color: var(--color-text);
    margin-bottom: var(--space-2);
}
.form-label .required { color: var(--color-danger); }

.form-control, .form-input, .form-select, .form-textarea {
    width: 100%;
    padding: 10px 14px;
    font-size: var(--text-base);
    background: var(--color-bg-elev);
    color: var(--color-text);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    transition: border-color var(--transition-base), box-shadow var(--transition-base);
}
.form-control:focus, .form-input:focus, .form-select:focus, .form-textarea:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px var(--color-primary-soft);
}
.form-textarea { min-height: 120px; resize: vertical; line-height: var(--leading-normal); }
.form-control::placeholder { color: var(--color-text-dim); }

.form-help { font-size: var(--text-xs); color: var(--color-text-muted); margin-top: var(--space-2); }
.form-error { font-size: var(--text-xs); color: var(--color-danger); margin-top: var(--space-2); }

.form-check { display: flex; align-items: center; gap: var(--space-2); cursor: pointer; }
.form-check input[type="checkbox"], .form-check input[type="radio"] {
    accent-color: var(--color-primary);
    width: 16px; height: 16px;
}

/* ========== CARDS ========== */
.card {
    background: var(--color-bg-elev);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
}
.card-body { padding: var(--space-6); }
.card-header {
    padding: var(--space-5) var(--space-6);
    border-bottom: 1px solid var(--color-border);
    display: flex; justify-content: space-between; align-items: center;
    gap: var(--space-3);
}
.card-header h3, .card-header h4 { margin: 0; font-size: var(--text-lg); }
.card-footer {
    padding: var(--space-4) var(--space-6);
    border-top: 1px solid var(--color-border);
    background: var(--color-bg-elev-2);
    border-radius: 0 0 var(--radius-lg) var(--radius-lg);
}

/* ========== BADGES ========== */
.badge {
    display: inline-flex;
    align-items: center;
    gap: var(--space-1);
    padding: 3px 10px;
    font-size: var(--text-xs);
    font-weight: var(--weight-semi);
    border-radius: var(--radius-full);
    background: var(--color-bg-elev-2);
    color: var(--color-text-muted);
    border: 1px solid var(--color-border);
}
.badge-primary { background: var(--color-primary-soft); color: var(--color-primary-text); border-color: transparent; }
.badge-accent { background: var(--color-accent-soft); color: var(--color-accent-text); border-color: transparent; }
.badge-warning { background: var(--color-warning-soft); color: var(--color-warning-text); border-color: transparent; }
.badge-danger { background: var(--color-danger-soft); color: var(--color-danger-text); border-color: transparent; }
.badge-info { background: var(--color-info-soft); color: var(--color-info-text); border-color: transparent; }

/* ========== ALERTS ========== */
.alert {
    padding: var(--space-4) var(--space-5);
    border-radius: var(--radius-md);
    border: 1px solid transparent;
    margin-bottom: var(--space-4);
    display: flex; gap: var(--space-3); align-items: flex-start;
    font-size: var(--text-sm);
}
.alert-success { background: var(--color-accent-soft); color: var(--color-accent-text); border-color: var(--color-accent); }
.alert-warning { background: var(--color-warning-soft); color: var(--color-warning-text); border-color: var(--color-warning); }
.alert-danger { background: var(--color-danger-soft); color: var(--color-danger-text); border-color: var(--color-danger); }
.alert-info { background: var(--color-info-soft); color: var(--color-info-text); border-color: var(--color-info); }

/* ========== TABLES ========== */
.table-wrap {
    background: var(--color-bg-elev);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-xs);
}
.table-scroll { overflow-x: auto; }
.table {
    width: 100%;
    border-collapse: collapse;
    font-size: var(--text-sm);
}
.table th, .table td { padding: 12px 16px; text-align: left; }
.table thead th {
    background: var(--color-bg-elev-2);
    color: var(--color-text-muted);
    font-weight: var(--weight-semi);
    text-transform: uppercase;
    font-size: var(--text-xs);
    letter-spacing: 0.05em;
    border-bottom: 1px solid var(--color-border);
}
.table tbody tr { border-top: 1px solid var(--color-divider); }
.table tbody tr:hover { background: var(--color-bg-hover); }
.table tbody td { color: var(--color-text); vertical-align: middle; }

/* ========== UTILITIES ========== */
.text-muted { color: var(--color-text-muted); }
.text-dim { color: var(--color-text-dim); }
.text-primary { color: var(--color-primary-text); }
.text-success { color: var(--color-accent-text); }
.text-warning { color: var(--color-warning-text); }
.text-danger { color: var(--color-danger-text); }

.text-xs { font-size: var(--text-xs); }
.text-sm { font-size: var(--text-sm); }
.text-md { font-size: var(--text-md); }
.text-lg { font-size: var(--text-lg); }
.text-xl { font-size: var(--text-xl); }

.font-medium { font-weight: var(--weight-medium); }
.font-semi   { font-weight: var(--weight-semi); }
.font-bold   { font-weight: var(--weight-bold); }

.text-center { text-align: center; }
.text-right { text-align: right; }
.text-left { text-align: left; }

.flex { display: flex; }
.inline-flex { display: inline-flex; }
.grid { display: grid; }
.block { display: block; }
.hidden { display: none; }

.items-center { align-items: center; }
.items-start { align-items: flex-start; }
.items-end { align-items: flex-end; }
.justify-between { justify-content: space-between; }
.justify-center { justify-content: center; }
.justify-end { justify-content: flex-end; }
.flex-wrap { flex-wrap: wrap; }
.flex-1 { flex: 1; }
.gap-1 { gap: var(--space-1); }
.gap-2 { gap: var(--space-2); }
.gap-3 { gap: var(--space-3); }
.gap-4 { gap: var(--space-4); }
.gap-5 { gap: var(--space-5); }
.gap-6 { gap: var(--space-6); }

.mt-1 { margin-top: var(--space-1); }
.mt-2 { margin-top: var(--space-2); }
.mt-3 { margin-top: var(--space-3); }
.mt-4 { margin-top: var(--space-4); }
.mt-5 { margin-top: var(--space-5); }
.mt-6 { margin-top: var(--space-6); }
.mt-8 { margin-top: var(--space-8); }
.mb-1 { margin-bottom: var(--space-1); }
.mb-2 { margin-bottom: var(--space-2); }
.mb-3 { margin-bottom: var(--space-3); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-5 { margin-bottom: var(--space-5); }
.mb-6 { margin-bottom: var(--space-6); }
.mb-8 { margin-bottom: var(--space-8); }

.w-full { width: 100%; }
.h-full { height: 100%; }

.rounded { border-radius: var(--radius-md); }
.rounded-lg { border-radius: var(--radius-lg); }
.rounded-xl { border-radius: var(--radius-xl); }
.rounded-full { border-radius: var(--radius-full); }

.shadow-sm { box-shadow: var(--shadow-sm); }
.shadow-md { box-shadow: var(--shadow-md); }
.shadow-lg { box-shadow: var(--shadow-lg); }

/* ========== ANIMATIONS ========== */
@keyframes fadeIn { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: translateY(0); } }
@keyframes spin { to { transform: rotate(360deg); } }
@keyframes pulse { 0%, 100% { opacity: 1; } 50% { opacity: .4; } }

.animate-fadeIn { animation: fadeIn .35s ease; }
.spinner {
    width: 18px; height: 18px;
    border: 2px solid var(--color-border);
    border-top-color: var(--color-primary);
    border-radius: 50%;
    animation: spin .7s linear infinite;
}

/* ========== THEME TOGGLE ========== */
.theme-toggle {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 38px; height: 38px;
    border-radius: var(--radius-full);
    background: var(--color-bg-elev-2);
    color: var(--color-text-muted);
    border: 1px solid var(--color-border);
    cursor: pointer;
    transition: all var(--transition-base);
}
.theme-toggle:hover { color: var(--color-text); border-color: var(--color-border-strong); }
.theme-toggle .sun { display: block; }
.theme-toggle .moon { display: none; }
[data-theme="dark"] .theme-toggle .sun { display: none; }
[data-theme="dark"] .theme-toggle .moon { display: block; }

/* ========== PRINT ========== */
@media print {
    body { background: white; color: black; }
    .no-print, .sidebar, .topbar, .btn { display: none !important; }
}