/* =============================================
   SchoolTools Survey - Base CSS
   Reset, typography, CSS custom properties
   Mobile-first design from DESIGN.md
   ============================================= */

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

html {
    font-size: 16px;
    -webkit-text-size-adjust: 100%;
    -moz-text-size-adjust: 100%;
}

body {
    font-family: var(--font-sans);
    font-size: var(--text-base);
    line-height: 1.6;
    color: var(--text);
    background: var(--bg);
    min-height: 100vh;
}

img, svg {
    max-width: 100%;
    display: block;
}

a {
    color: var(--primary-500);
    text-decoration: none;
}
a:hover {
    text-decoration: underline;
}

/* --- CSS Custom Properties --- */
:root {
    /* Fonts */
    --font-sans: system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
    --font-mono: 'SF Mono', Consolas, 'Liberation Mono', monospace;

    /* Text sizes */
    --text-xs: 0.75rem;
    --text-sm: 0.875rem;
    --text-base: 1rem;
    --text-lg: 1.125rem;
    --text-xl: 1.25rem;
    --text-2xl: 1.5rem;
    --text-3xl: 1.875rem;

    /* Primary — uNiek Solutions */
    --primary-50: #f4f8e6;
    --primary-100: #e8f1cc;
    --primary-200: #d2e49a;
    --primary-300: #bcd668;
    --primary-400: #b7cf4c;
    --primary-500: #aaca38;
    --primary-600: #8ba22d;
    --primary-700: #6d7e23;

    /* Neutral */
    --gray-50: #f9fafb;
    --gray-100: #f3f4f6;
    --gray-200: #e5e7eb;
    --gray-300: #d1d5db;
    --gray-400: #9ca3af;
    --gray-500: #6b7280;
    --gray-600: #4b5563;
    --gray-700: #374151;
    --gray-800: #1f2937;
    --gray-900: #111827;

    /* Semantic */
    --success: #22c55e;
    --success-light: #dcfce7;
    --warning: #f59e0b;
    --warning-light: #fef3c7;
    --danger: #ef4444;
    --danger-light: #fee2e2;
    --info: #3b82f6;
    --info-light: #dbeafe;

    /* Surfaces */
    --bg: #ffffff;
    --bg-alt: var(--gray-50);
    --border: var(--gray-200);
    --text: var(--gray-900);
    --text-muted: var(--gray-500);
    --text-light: var(--gray-400);

    /* Spacing */
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.25rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-10: 2.5rem;
    --space-12: 3rem;

    /* Layout */
    --radius: 0.5rem;
    --radius-sm: 0.25rem;
    --radius-lg: 0.75rem;
    --radius-full: 9999px;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.05);
    --shadow: 0 1px 3px rgba(0,0,0,0.1), 0 1px 2px rgba(0,0,0,0.06);
    --shadow-md: 0 4px 6px rgba(0,0,0,0.1), 0 2px 4px rgba(0,0,0,0.06);
    --shadow-lg: 0 10px 15px rgba(0,0,0,0.1), 0 4px 6px rgba(0,0,0,0.05);

    /* Transitions */
    --transition: 150ms ease;
    --transition-slow: 300ms ease;

    /* Container */
    --container-sm: 640px;
    --container-md: 768px;
    --container-lg: 1024px;
    --container-xl: 1280px;
}

/* --- Typography --- */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.3;
    color: var(--text);
}

h1 { font-size: var(--text-3xl); }
h2 { font-size: var(--text-2xl); }
h3 { font-size: var(--text-xl); }
h4 { font-size: var(--text-lg); }

p { margin-bottom: var(--space-4); }
p:last-child { margin-bottom: 0; }

small, .text-sm { font-size: var(--text-sm); }
.text-xs { font-size: var(--text-xs); }
.text-muted { color: var(--text-muted); }
.text-center { text-align: center; }
.text-right { text-align: right; }

/* --- Layout utilities --- */
.container {
    width: 100%;
    max-width: var(--container-lg);
    margin: 0 auto;
    padding: 0 var(--space-4);
}

.container-sm {
    max-width: var(--container-sm);
}

.flex { display: flex; }
.flex-col { flex-direction: column; }
.flex-wrap { flex-wrap: wrap; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.justify-center { justify-content: center; }
.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-6 { gap: var(--space-6); }

/* --- Grid System --- */
.grid {
    display: grid;
    gap: var(--space-4);
    grid-template-columns: 1fr;
}

@media (min-width: 768px) {
    .grid-2 { grid-template-columns: repeat(2, 1fr); }
    .grid-3 { grid-template-columns: repeat(3, 1fr); }
}

@media (min-width: 1024px) {
    .grid-4 { grid-template-columns: repeat(4, 1fr); }
}

/* --- Spacing helpers --- */
.mt-2 { margin-top: var(--space-2); }
.mt-4 { margin-top: var(--space-4); }
.mt-6 { margin-top: var(--space-6); }
.mt-8 { margin-top: var(--space-8); }
.mb-2 { margin-bottom: var(--space-2); }
.mb-4 { margin-bottom: var(--space-4); }
.mb-6 { margin-bottom: var(--space-6); }
.p-4 { padding: var(--space-4); }
.p-6 { padding: var(--space-6); }

/* --- Visibility --- */
.hidden { display: none !important; }

@media (max-width: 767px) {
    .hide-mobile { display: none !important; }
}
@media (min-width: 768px) {
    .hide-desktop { display: none !important; }
}

/* --- Responsive padding --- */
@media (min-width: 768px) {
    .container {
        padding: 0 var(--space-6);
    }
}