@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;600;700;800&display=swap');

:root {
    --primary: #6366f1; 
    --accent: #ec4899;
    --bg-dark: #0f172a;
    --card-bg: #1e293b;
    --glass: rgba(30, 41, 59, 0.7);
    --gradient: linear-gradient(135deg, #6366f1 0%, #a855f7 50%, #ec4899 100%);
}

* { margin: 0; padding: 0; box-sizing: border-box; font-family: 'Inter', sans-serif; }

body { 
    background-color: var(--bg-dark); 
    color: #f8fafc; 
    min-height: 100vh; 
    line-height: 1.6;
    background-image: radial-gradient(circle at top right, rgba(99, 102, 241, 0.15), transparent),
                      radial-gradient(circle at bottom left, rgba(236, 72, 153, 0.1), transparent);
}

/* Header & Logo */
header { 
    display: flex; justify-content: space-between; align-items: center; 
    padding: 0 5%; height: 80px; border-bottom: 1px solid rgba(255,255,255,0.05); 
    background: rgba(15, 23, 42, 0.8); backdrop-filter: blur(10px);
    position: sticky; top: 0; z-index: 100;
}
.logo { font-size: 24px; font-weight: 800; letter-spacing: -1px; }
.logo span { background: var(--gradient); -webkit-background-clip: text; -webkit-text-fill-color: transparent; }

/* Main Container */
main { max-width: 900px; margin: 60px auto; padding: 0 20px; text-align: center; }
h1 { font-size: clamp(32px, 5vw, 56px); font-weight: 800; margin-bottom: 15px; letter-spacing: -2px; line-height: 1.1; }
h2 { color: #94a3b8; font-size: 18px; font-weight: 400; margin-bottom: 50px; }

/* The Tool Card */
.card { 
    background: var(--glass);
    padding: 40px; 
    border-radius: 28px; 
    border: 1px solid rgba(255, 255, 255, 0.1); 
    box-shadow: 0 25px 50px -12px rgba(0,0,0,0.5);
    backdrop-filter: blur(12px);
}

/* Upload Area */
.upload-zone { 
    border: 2px dashed rgba(99, 102, 241, 0.3); 
    padding: 50px 20px; 
    border-radius: 20px; 
    cursor: pointer; 
    transition: all 0.3s ease; 
    margin-bottom: 30px;
    background: rgba(255,255,255,0.02);
}
.upload-zone:hover { border-color: var(--primary); background: rgba(99, 102, 241, 0.05); transform: translateY(-2px); }
.upload-zone i { font-size: 48px; color: var(--primary); margin-bottom: 15px; }

/* Layout Grid */
.tool-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin-bottom: 20px; }
.control-group { background: rgba(0, 0, 0, 0.2); padding: 25px; border-radius: 16px; text-align: left; border: 1px solid rgba(255,255,255,0.05); }
.label { font-size: 11px; font-weight: 700; color: #64748b; margin-bottom: 15px; display: block; text-transform: uppercase; letter-spacing: 1px; }

/* Inputs with consistent margins */
.input-row { display: flex; gap: 12px; margin-bottom: 15px; }
.input-row:last-of-type { margin-bottom: 0; }
input[type="number"], input[type="text"], select { 
    width: 100%; background: #0f172a; border: 1px solid #334155; 
    color: white; padding: 14px; border-radius: 10px; outline: none; transition: 0.2s;
}
input:focus { border-color: var(--primary); box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2); }

/* Buttons */
.btn-convert { 
    flex: 1; background: var(--gradient); border: none; padding: 20px; 
    border-radius: 14px; color: white; font-weight: 700; font-size: 16px; 
    cursor: pointer; transition: 0.3s ease; box-shadow: 0 10px 20px -10px rgba(99, 102, 241, 0.5);
}
.btn-convert:hover { transform: translateY(-2px); filter: brightness(1.1); box-shadow: 0 15px 30px -10px rgba(99, 102, 241, 0.6); }

/* Refined Footer */
.main-footer { margin-top: 100px; padding: 60px 5% 40px; border-top: 1px solid rgba(255,255,255,0.05); background: #0b1120; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 40px; max-width: 1100px; margin: 0 auto; text-align: left; }
.footer-col h3 { font-size: 12px; color: #94a3b8; margin-bottom: 20px; text-transform: uppercase; letter-spacing: 2px; }
.footer-col ul { list-style: none; }
.footer-col ul li { margin-bottom: 12px; }
.footer-col a { color: #64748b; text-decoration: none; transition: 0.3s; font-size: 14px; }
.footer-col a:hover { color: var(--primary); }

@media (max-width: 768px) {
    .tool-grid, .footer-grid { grid-template-columns: 1fr; }
    header { padding: 0 20px; }
}