/* ============================================
   ENTANGLEUP - Global Style Sheet
   Variables, Reset, and Base Styles
   ============================================ */

:root {
    /* Material Design 3 Color System */
    --md-ref-pal-sys-light-primary: #6750a4;
    --md-ref-pal-sys-light-secondary: #625b71;
    --md-ref-pal-sys-light-tertiary: #7d5260;
    --md-ref-pal-sys-light-error: #b3261e;
    --md-ref-pal-sys-light-background: #f8f9fa;
    --md-ref-pal-sys-light-surface: #ffffff;
    --md-ref-pal-sys-light-surface-variant: #e7e0ec;
    --md-ref-pal-sys-light-on-primary: #ffffff;
    --md-ref-pal-sys-light-on-surface: #1c1b1f;
    --md-ref-pal-sys-light-on-surface-variant: #49454f;
    
    --md-sys-color-primary: var(--md-ref-pal-sys-light-primary);
    --md-sys-color-secondary: var(--md-ref-pal-sys-light-secondary);
    --md-sys-color-tertiary: var(--md-ref-pal-sys-light-tertiary);
    --md-sys-color-error: var(--md-ref-pal-sys-light-error);
    --md-sys-color-background: var(--md-ref-pal-sys-light-background);
    --md-sys-color-surface: var(--md-ref-pal-sys-light-surface);
    --md-sys-color-surface-variant: var(--md-ref-pal-sys-light-surface-variant);
    --md-sys-color-on-primary: var(--md-ref-pal-sys-light-on-primary);
    --md-sys-color-on-surface: var(--md-ref-pal-sys-light-on-surface);
    --md-sys-color-on-surface-variant: var(--md-ref-pal-sys-light-on-surface-variant);
    
    /* Elevation */
    --md-sys-elevation-level1: 0 2px 1px -1px rgba(0,0,0,0.2), 0 1px 1px 0 rgba(0,0,0,0.14), 0 1px 3px 0 rgba(0,0,0,0.12);
    --md-sys-elevation-level2: 0 3px 1px -2px rgba(0,0,0,0.2), 0 2px 2px 0 rgba(0,0,0,0.14), 0 1px 5px 0 rgba(0,0,0,0.12);
    --md-sys-elevation-level3: 0 3px 3px -2px rgba(0,0,0,0.2), 0 3px 4px 0 rgba(0,0,0,0.14), 0 1px 8px 0 rgba(0,0,0,0.12);
    
    /* Shape */
    --md-sys-shape-corner-extra-large: 28px;
    --md-sys-shape-corner-large: 16px;
    --md-sys-shape-corner-medium: 12px;
    --md-sys-shape-corner-small: 8px;
    --md-sys-shape-corner-extra-small: 4px;
}

/* ── Reset ── */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* ── Base ── */
body {
    font-family: 'Inter', system-ui, sans-serif;
    background-color: var(--md-sys-color-background);
    color: var(--md-sys-color-on-surface);
    line-height: 1.6;
    min-height: 100vh;
}

a {
    text-decoration: none;
    color: inherit;
}

ul, ol {
    list-style: none;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

/* ── Container ── */
.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 24px 16px;
}

/* ── Typography ── */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    letter-spacing: -0.02em;
    color: var(--md-sys-color-on-surface);
}

h1 { font-size: 2.4rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

p {
    color: var(--md-sys-color-on-surface-variant);
    font-size: 1rem;
    line-height: 1.7;
}

/* ── Buttons ── */
.btn {
    padding: 10px 20px;
    border-radius: var(--md-sys-shape-corner-medium);
    border: none;
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
    font-family: 'Inter', system-ui, sans-serif;
}

.btn-primary {
    background: var(--md-sys-color-primary);
    color: var(--md-sys-color-on-primary);
}

.btn-primary:hover {
    background: #554288;
}

.btn-secondary {
    background: var(--md-sys-color-surface-variant);
    color: var(--md-sys-color-on-surface);
}

.btn-secondary:hover {
    background: #dcd7e0;
}

.btn .material-icons {
    font-size: 1rem;
}

/* ── Badges ── */
.badge {
    background: #f3f0f7;
    color: #1c1b1f;
    padding: 6px 16px;
    border-radius: 40px;
    font-size: 0.8rem;
    font-weight: 500;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

.badge .material-icons {
    font-size: 1rem;
    color: #6750a4;
}

.badge.primary {
    background: #6750a4;
    color: #fff;
}

.badge.primary .material-icons {
    color: #fff;
}

.badge-group {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-top: 16px;
}

/* ── Utility ── */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    border: 0;
}

.text-center { text-align: center; }
.text-muted { color: var(--md-sys-color-on-surface-variant); }

/* ── Animations ── */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes slideUp {
    from { opacity: 0; transform: translateY(40px); }
    to { opacity: 1; transform: translateY(0); }
}

/* ── Responsive ── */
@media (max-width: 768px) {
    h1 { font-size: 1.8rem; }
    h2 { font-size: 1.6rem; }
    h3 { font-size: 1.3rem; }
    .container { padding: 16px; }
}

@media (max-width: 480px) {
    h1 { font-size: 1.5rem; }
    h2 { font-size: 1.3rem; }
}