:root {
    --bg: #0D1117;
    --accent: #00C896;
    --card: rgba(22, 31, 42, 0.7);
    --text: #FFFFFF;
}

body { background: var(--bg); color: var(--text); font-family: 'DM Sans', sans-serif; margin: 0; line-height: 1.6; }
h1, h2 { font-family: 'Syne', sans-serif; color: var(--accent); text-align: center; }

.container { max-width: 1000px; margin: 0 auto; padding: 20px; }

.top-nav { display: flex; justify-content: space-between; align-items: center; padding: 20px 0; border-bottom: 1px solid rgba(255,255,255,0.1); margin-bottom: 30px; }
.brand { font-size: 24px; font-weight: bold; color: #fff; text-decoration: none; }
.brand span { color: var(--accent); }
.nav-links a { color: #fff; text-decoration: none; margin-left: 20px; opacity: 0.8; font-size: 0.9rem; transition: 0.3s; }
.nav-links a:hover { color: var(--accent); opacity: 1; }

.subtitle { text-align: center; opacity: 0.7; margin-top: -10px; margin-bottom: 30px; }

.tool-card {
    background: var(--card); backdrop-filter: blur(15px);
    border: 1px solid rgba(0, 200, 150, 0.3); padding: 40px; border-radius: 24px;
}

.tabs { display: flex; gap: 10px; margin-bottom: 25px; }
.tab-btn { flex: 1; padding: 12px; border: none; border-radius: 8px; cursor: pointer; background: rgba(255,255,255,0.05); color: #fff; transition: 0.3s; }
.tab-btn.active { background: var(--accent); color: #000; font-weight: bold; }

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

.input-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; }
label { display: block; font-size: 0.85rem; opacity: 0.7; margin-bottom: 5px; }
input { width: 100%; padding: 14px; background: #161B22; border: 1px solid #30363D; border-radius: 8px; color: #fff; box-sizing: border-box; font-size: 1rem; }
input:focus { border-color: var(--accent); outline: none; }

.result-box { margin: 30px 0; padding: 30px; background: rgba(0, 200, 150, 0.1); border-radius: 12px; text-align: center; border: 1px dashed var(--accent); }
#displayResult { font-size: 3.5rem; color: var(--accent); font-weight: bold; }

.hub-directory { margin-top: 60px; padding: 40px 0; border-top: 1px solid rgba(255,255,255,0.05); }
.hub-links { display: grid; grid-template-columns: repeat(auto-fill, minmax(160px, 1fr)); gap: 12px; margin-top: 25px; }
.hub-links a { background: rgba(255,255,255,0.05); border: 1px solid rgba(255,255,255,0.1); color: #fff; padding: 12px; border-radius: 8px; text-decoration: none; font-size: 0.8rem; text-align: center; transition: 0.3s; }
.hub-links a:hover { background: var(--accent); color: #000; transform: translateY(-3px); }

.formula-box { background: rgba(255,255,255,0.03); padding: 25px; border-radius: 12px; border-left: 5px solid var(--accent); margin-top: 20px; }
code { background: #000; padding: 3px 8px; border-radius: 4px; color: var(--accent); }
.faq-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin-top: 30px; }
.faq-item { background: #161B22; padding: 20px; border-radius: 12px; border: 1px solid rgba(255,255,255,0.05); }
.faq-item strong { color: var(--accent); display: block; margin-bottom: 8px; }

.footer { text-align: center; margin-top: 80px; padding: 40px; border-top: 1px solid rgba(255,255,255,0.1); font-size: 0.9rem; opacity: 0.6; }
.footer a { color: var(--accent); text-decoration: none; }

@media (max-width: 600px) { .input-grid, .faq-grid { grid-template-columns: 1fr; } }