@import url('variables.css');

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
    margin: 0;
    font-family: var(--font-body);
    background: var(--bg-base);
    color: var(--text-primary);
    -webkit-font-smoothing: antialiased;
    transition: background var(--transition-base), color var(--transition-base);
    min-height: 100vh;
}
h1, h2, h3, h4 { font-family: var(--font-display); font-weight: 700; margin: 0 0 var(--space-3); line-height: 1.2; }
p { margin: 0 0 var(--space-3); color: var(--text-secondary); }
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
button { font-family: inherit; }
::-webkit-scrollbar { width: 10px; height: 10px; }
::-webkit-scrollbar-thumb { background: var(--scrollbar-thumb); border-radius: var(--radius-pill); }

.container { max-width: 1160px; margin: 0 auto; padding: 0 var(--space-5); }
.skip-link { position: absolute; left: -999px; top: 0; background: var(--accent); color: #fff; padding: var(--space-2) var(--space-4); z-index: 999; }
.skip-link:focus { left: var(--space-3); top: var(--space-3); }

/* ---------- Glass / card system ---------- */
.glass {
    background: var(--bg-glass);
    backdrop-filter: blur(20px) saturate(160%);
    -webkit-backdrop-filter: blur(20px) saturate(160%);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-lg);
}
.card {
    background: var(--bg-elevated);
    border: 1px solid var(--border-glass);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
    padding: var(--space-5);
    transition: transform var(--transition-base), box-shadow var(--transition-base);
}
.card--hover:hover { transform: translateY(-4px); box-shadow: var(--shadow-md); }

/* ---------- Navbar ---------- */
.navbar {
    position: sticky; top: 0; z-index: 100;
    display: flex; align-items: center; justify-content: space-between;
    padding: var(--space-3) var(--space-5);
    background: var(--bg-glass-strong);
    backdrop-filter: blur(20px) saturate(160%);
    -webkit-backdrop-filter: blur(20px) saturate(160%);
    border-bottom: 1px solid var(--border-glass);
}
.navbar__brand { display: flex; align-items: center; gap: var(--space-2); font-family: var(--font-display); font-weight: 800; font-size: 1.25rem; }
.navbar__brand-mark { width: 34px; height: 34px; border-radius: var(--radius-sm); flex-shrink: 0; }
.navbar__links { display: flex; gap: var(--space-4); align-items: center; }
.navbar__link { padding: var(--space-2) var(--space-3); border-radius: var(--radius-pill); color: var(--text-secondary); font-weight: 600; font-size: 0.9rem; transition: background var(--transition-fast), color var(--transition-fast); }
.navbar__link:hover, .navbar__link.is-active { background: var(--bg-glass); color: var(--text-primary); }
.navbar__actions { display: flex; align-items: center; gap: var(--space-3); }

/* ---------- Buttons ---------- */
.btn {
    display: inline-flex; align-items: center; justify-content: center; gap: var(--space-2);
    border: none; border-radius: var(--radius-pill); cursor: pointer;
    padding: var(--space-3) var(--space-5); font-weight: 700; font-size: 0.95rem;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast), opacity var(--transition-fast);
    position: relative; overflow: hidden;
}
.btn:active { transform: scale(0.97); }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }
.btn--primary { background: var(--gradient-brand); color: #fff; box-shadow: var(--shadow-glow); }
.btn--primary:hover { box-shadow: var(--shadow-lg); }
.btn--ghost { background: var(--bg-glass); color: var(--text-primary); border: 1px solid var(--border-glass); }
.btn--ghost:hover { background: var(--bg-glass-strong); }
.btn--block { width: 100%; }
.btn--sm { padding: var(--space-2) var(--space-4); font-size: 0.85rem; }

/* Ripple micro-interaction */
.btn .ripple {
    position: absolute; border-radius: 50%; transform: scale(0);
    background: rgba(255,255,255,0.5); animation: ripple 600ms ease-out;
    pointer-events: none;
}
@keyframes ripple { to { transform: scale(4); opacity: 0; } }

/* ---------- Theme toggle ---------- */
.theme-toggle { display: flex; gap: 2px; background: var(--bg-glass); border-radius: var(--radius-pill); padding: 3px; border: 1px solid var(--border-glass); }
.theme-toggle button {
    border: none; background: transparent; color: var(--text-muted); padding: 6px 10px; border-radius: var(--radius-pill);
    cursor: pointer; font-size: 0.95rem; transition: background var(--transition-fast), color var(--transition-fast);
}
.theme-toggle button.is-active { background: var(--gradient-brand); color: #fff; }

/* ---------- Hero / landing ---------- */
.hero { padding: var(--space-8) 0 var(--space-7); text-align: center; }
.hero__badge {
    display: inline-flex; align-items: center; gap: var(--space-2); padding: var(--space-2) var(--space-4);
    background: var(--bg-glass); border: 1px solid var(--border-glass); border-radius: var(--radius-pill);
    font-size: 0.8rem; font-weight: 700; color: var(--accent); margin-bottom: var(--space-5);
}
.hero h1 { font-size: clamp(2.2rem, 5vw, 3.6rem); background: var(--gradient-brand); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero p.lead { font-size: 1.15rem; max-width: 640px; margin: 0 auto var(--space-6); }
.hero__cta { display: flex; gap: var(--space-3); justify-content: center; flex-wrap: wrap; }

.grid { display: grid; gap: var(--space-5); }
.grid--3 { grid-template-columns: repeat(3, 1fr); }
.grid--4 { grid-template-columns: repeat(4, 1fr); }
@media (max-width: 900px) { .grid--3, .grid--4 { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 600px) { .grid--3, .grid--4 { grid-template-columns: 1fr; } .navbar__links { display: none; } }

.badge { display: inline-block; padding: 2px 10px; border-radius: var(--radius-pill); font-size: 0.72rem; font-weight: 800; letter-spacing: 0.02em; }
.badge--premium { background: linear-gradient(135deg, #FBBF24, #F59E0B); color: #1a1a1a; }
.badge--streak { background: var(--gradient-warm); color: #fff; }

/* ---------- Skeleton loaders ---------- */
.skeleton { position: relative; overflow: hidden; background: var(--border-glass); border-radius: var(--radius-sm); }
.skeleton::after {
    content: ''; position: absolute; inset: 0; transform: translateX(-100%);
    background: linear-gradient(90deg, transparent, rgba(255,255,255,0.25), transparent);
    animation: shimmer 1.4s infinite;
}
@keyframes shimmer { 100% { transform: translateX(100%); } }

/* ---------- Toast ---------- */
.toast-stack { position: fixed; bottom: var(--space-5); right: var(--space-5); display: flex; flex-direction: column; gap: var(--space-2); z-index: 999; }
.toast {
    background: var(--bg-glass-strong); border: 1px solid var(--border-glass); color: var(--text-primary);
    padding: var(--space-3) var(--space-4); border-radius: var(--radius-md); box-shadow: var(--shadow-md);
    animation: toast-in var(--transition-slow);
}
.toast--error { border-color: #EF4444; }
@keyframes toast-in { from { opacity: 0; transform: translateY(12px); } to { opacity: 1; transform: translateY(0); } }

/* ---------- Footer ---------- */
.footer { padding: var(--space-7) 0 var(--space-6); border-top: 1px solid var(--border-glass); margin-top: var(--space-8); color: var(--text-muted); font-size: 0.9rem; }
.footer__links { display: flex; gap: var(--space-4); flex-wrap: wrap; margin-top: var(--space-3); }

/* ---------- PWA install prompt ---------- */
.install-banner {
    position: fixed; left: 50%; bottom: var(--space-5); transform: translateX(-50%) translateY(150%);
    display: flex; align-items: center; gap: var(--space-4); padding: var(--space-3) var(--space-4);
    z-index: 998; transition: transform var(--transition-slow); box-shadow: var(--shadow-lg);
}
.install-banner.is-visible { transform: translateX(-50%) translateY(0); }

.visually-hidden { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0,0,0,0); }