/**
 * AbhiHub — 02_base.css
 * Global reset, body, typography, scrollbar, selection, accessibility.
 * Depends on: 01_tokens.css
 */

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-primary);
    background: var(--gradient-surface);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
    padding-bottom: var(--nav-bottom-height);
}

/* ── Typography ── */
h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    line-height: 1.3;
    color: var(--text-primary);
    margin-bottom: var(--space-4);
}

h1 { font-size: var(--text-4xl); }
h2 { font-size: var(--text-3xl); }
h3 { font-size: var(--text-2xl); }
h4 { font-size: var(--text-xl); }
h5 { font-size: var(--text-lg); }
h6 { font-size: var(--text-base); }

p {
    margin-bottom: var(--space-4);
    color: var(--text-secondary);
}

a {
    color: var(--primary-600);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover { color: var(--primary-700); }

/* ── Scrollbar ── */
::-webkit-scrollbar       { width: 6px; height: 6px; }
::-webkit-scrollbar-track { background: var(--bg-tertiary); }
::-webkit-scrollbar-thumb {
    background: var(--primary-400);
    border-radius: var(--radius-full);
}
::-webkit-scrollbar-thumb:hover { background: var(--primary-600); }

/* ── Selection ── */
::selection         { background: var(--brand-yellow); color: var(--text-dark); }
::-moz-selection    { background: var(--brand-yellow); color: var(--text-dark); }

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

.skip-nav {
    position: absolute;
    top: -40px; left: 6px;
    background: var(--text-dark);
    color: var(--text-inverse);
    padding: 8px;
    text-decoration: none;
    border-radius: var(--radius-sm);
    z-index: 1002;
    font-weight: 600;
    transition: top var(--transition-fast);
}
.skip-nav:focus { top: 6px; outline: 2px solid var(--brand-yellow); }

:focus-visible {
    outline: 2px solid var(--primary-600);
    outline-offset: 2px;
}

/* ── Offline Banner ── */
#offline-banner {
    display: none;
    position: fixed;
    top: 0; left: 0;
    width: 100%;
    background: var(--accent-red);
    color: var(--text-inverse);
    text-align: center;
    padding: 10px;
    z-index: 10000;
    font-weight: 700;
    box-shadow: var(--shadow-md);
}

/* ── Animations ── */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to   { opacity: 1; transform: translateY(0); }
}

@keyframes slideUp {
    from { opacity: 0; transform: translateY(30px) scale(0.95); }
    to   { opacity: 1; transform: translateY(0) scale(1); }
}

@keyframes slideUpBounce {
    0%   { opacity: 0; transform: translateY(50px) scale(0.8); }
    60%  { opacity: 1; transform: translateY(-10px) scale(1.05); }
    100% { opacity: 1; transform: translateY(0) scale(1); }
}

@keyframes slideDown {
    from { opacity: 0; transform: translateY(-10px); }
    to   { opacity: 1; transform: translateY(0); }
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

@keyframes pulse {
    0%, 100% { transform: scale(1); opacity: 1; }
    50%       { transform: scale(1.05); opacity: 0.9; }
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50%       { transform: translateY(-10px); }
}

@keyframes shimmer {
    0%   { background-position: -200% 0; }
    100% { background-position:  200% 0; }
}

.fade-in  { animation: fadeIn  0.3s ease-out; }
.slide-up { animation: slideUp 0.4s ease-out; }

/* ── Responsive base ── */
@media (max-width: 768px) {
    :root { font-size: 14px; }
    h1 { font-size: var(--text-3xl); }
    h2 { font-size: var(--text-2xl); }
    h3 { font-size: var(--text-xl); }
}