/* MyLLM.org - Non-Profit Open AI Foundation CSS Design System */
:root {
    --bg-dark: #07090e;
    --bg-surface: #0f141c;
    --bg-card: #18202c;
    --bg-card-hover: #222d3d;
    --border: #2a3648;
    --border-glow: #384b64;

    --emerald: #10b981;
    --emerald-hover: #059669;
    --emerald-glow: rgba(16, 185, 129, 0.2);

    --cyan: #06b6d4;
    --purple: #a855f7;

    --text-main: #f8fafc;
    --text-muted: #94a3b8;
    --text-dim: #64748b;

    --font-main: 'Inter', system-ui, -apple-system, sans-serif;
    --font-mono: 'JetBrains Mono', monospace;

    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body { background: var(--bg-dark); color: var(--text-main); font-family: var(--font-main); line-height: 1.6; min-height: 100vh; display: flex; flex-direction: column; }

h1, h2, h3, h4 { color: #fff; font-weight: 700; line-height: 1.25; }
a { color: var(--emerald); text-decoration: none; transition: color 0.2s; }
a:hover { color: #34d399; }

header { background: var(--bg-surface); border-bottom: 1px solid var(--border); position: sticky; top: 0; z-index: 50; backdrop-filter: blur(8px); }
.nav-container { max-width: 1280px; margin: 0 auto; padding: 1rem 1.5rem; display: flex; justify-content: space-between; align-items: center; }
.logo { font-size: 1.5rem; font-weight: 800; color: #fff; display: flex; align-items: center; gap: 0.5rem; }
.logo span { color: var(--emerald); }

.nav-links { display: flex; gap: 1.5rem; align-items: center; list-style: none; }
.nav-links a { color: var(--text-muted); font-size: 0.95rem; font-weight: 500; cursor: pointer; }
.nav-links a:hover, .nav-links a.active { color: #fff; }

.btn { display: inline-flex; align-items: center; justify-content: center; gap: 0.5rem; padding: 0.65rem 1.35rem; font-size: 0.95rem; font-weight: 700; border-radius: var(--radius-md); border: none; cursor: pointer; text-decoration: none !important; transition: all 0.2s; }
.btn-emerald { background-color: var(--emerald) !important; color: #04120c !important; font-weight: 800; }
.btn-emerald:hover { background-color: #34d399 !important; color: #04120c !important; box-shadow: 0 0 20px rgba(52, 211, 153, 0.4); }
.btn-outline { background: transparent; border: 1px solid var(--border); color: #fff !important; }
.btn-outline:hover { border-color: var(--emerald); color: var(--emerald) !important; }
.btn-sm { padding: 0.5rem 1rem; font-size: 0.875rem; }

.hero { text-align: center; max-width: 900px; margin: 0 auto; padding: 4rem 1.5rem 3rem 1.5rem; }
.hero h1 { font-size: 3.2rem; font-weight: 800; margin-bottom: 1rem; line-height: 1.15; background: linear-gradient(135deg, #ffffff 0%, #a7f3d0 100%); -webkit-background-clip: text; -webkit-text-fill-color: transparent; }
.hero p { font-size: 1.2rem; color: var(--text-muted); margin-bottom: 2.5rem; }

.tabs-header { display: flex; border-bottom: 1px solid var(--border); margin-bottom: 2rem; gap: 1rem; overflow-x: auto; }
.tab-btn { padding: 0.85rem 1.5rem; background: transparent; border: none; border-bottom: 2px solid transparent; color: var(--text-muted); font-size: 1rem; font-weight: 600; cursor: pointer; transition: all 0.2s; white-space: nowrap; }
.tab-btn:hover { color: #fff; }
.tab-btn.active { color: var(--emerald); border-bottom-color: var(--emerald); }

.tab-content { display: none; }
.tab-content.active { display: block; }

.main-container { max-width: 1280px; margin: 0 auto; padding: 0 1.5rem 4rem 1.5rem; flex: 1; width: 100%; }

.card-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(350px, 1fr)); gap: 1.5rem; }
.card { background: var(--bg-surface); border: 1px solid var(--border); border-radius: var(--radius-lg); padding: 1.75rem; display: flex; flex-direction: column; justify-content: space-between; transition: transform 0.2s, border-color 0.2s; }
.card:hover { transform: translateY(-4px); border-color: var(--border-glow); }

.tool-card { background: var(--bg-surface); border: 1px solid var(--border); border-radius: var(--radius-xl); padding: 2rem; max-width: 900px; margin: 0 auto; }

.code-box { background: #000; border: 1px solid var(--border); border-radius: var(--radius-md); padding: 1.25rem; font-family: var(--font-mono); font-size: 0.9rem; color: #34d399; position: relative; overflow-x: auto; margin-top: 1rem; }

footer { background: var(--bg-surface); border-top: 1px solid var(--border); padding: 2rem 1.5rem; text-align: center; color: var(--text-muted); font-size: 0.9rem; }


/* WCAG 2.1 AA/AAA Accessibility Enhancements */
.skip-link {
    position: absolute;
    top: -100px;
    left: 1rem;
    background: #10b981;
    color: #000000 !important;
    font-weight: 800;
    padding: 0.75rem 1.25rem;
    z-index: 9999;
    border-radius: 0.375rem;
    transition: top 0.2s ease;
    text-decoration: none;
}
.skip-link:focus {
    top: 1rem;
    outline: 3px solid #ffffff;
    box-shadow: 0 0 15px rgba(16, 185, 129, 0.5);
}
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}
:focus-visible {
    outline: 3px solid #38bdf8 !important;
    outline-offset: 3px !important;
}