/* Base Styles */

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: #0f172a;
    color: #f8fafc;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
}

/* Header Section */

header {
    position: absolute;
    top: 20px;
    font-size: 1.5rem;
    font-weight: 700;
    letter-spacing: -0.025em;
    color: #38bdf8;
}

/* Main Section */

main {
    background-color: #1e293b;
    padding: 2.5rem;
    border-radius: 16px;
    box-shadow: 0 10px 25px -5px rgba(0, 0, 0, 0.3);
    width: 100%;
    max-width: 450px;
    border: 1px solid #334155;
    display: flex;
    flex-direction: column;
    align-items: center; 
}

#main-box {
    width: 100%;
}

#px-rem-converter, 
#base-converter, 
#hex-rgb-converter {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    width: 100%;
    gap: 12px;
}

#main-box img {
    display: block;
    margin: 5px auto;
    width: 24px;
    height: 24px;
}

#card-heading {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 5px;
    color: #38bdf8;
    text-align: center;
}

label {
    display: block;
    margin-bottom: 8px;
    font-size: 0.875rem;
    color: #94a3b8;
}

#app-selector {
    width: 100%;
    padding: 12px;
    border-radius: 8px;
    background-color: #334155;
    border: 1px solid #475569;
    color: white;
    margin-bottom: 2rem;
    cursor: pointer;
    outline: none;
}

#app-selector:focus {
    border-color: #38bdf8;
}


#main-box > div {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 15px;
}

#card-heading {
    font-size: 1.125rem;
    font-weight: 600;
    margin-bottom: 10px;
    color: #f1f5f9;
}


input {
    width: 100%;
    padding: 14px;
    border-radius: 8px;
    border: 1px solid #475569;
    background-color: #0f172a;
    color: #38bdf8;
    font-family: 'Courier New', Courier, monospace;
    font-size: 1rem;
    text-align: center;
    transition: all 0.2s;
}

input:focus {
    outline: none;
    border-color: #38bdf8;
    box-shadow: 0 0 0 2px rgba(56, 189, 248, 0.2);
}

.icon-swap {
    width: 24px;
    height: 24px;
    background-color: #38bdf8;
    mask: url("data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSIyNCIgaGVpZ2h0PSIyNCIgdmlld0JveD0iMCAwIDI0IDI0IiBmaWxsPSJub25lIiBzdHJva2U9ImN1cnJlbnRDb2xvciIgc3Ryb2tlLXdpZHRoPSIyIiBzdHJva2UtbGluZWNhcD0icm91bmQiIHN0cm9rZS1saW5lam9pbj0icm91bmQiPjxwYXRoIGQ9Im0yMSAxNi00IDQtNC00Ii8+PHBhdGggZD0iTTE3IDIwVjQiLz48cGF0aCBkPSJtMyA4IDQtNCA0IDgiLz48cGF0aCBkPSJNNyA0djE2Ii8+PC9zdmc+");
    -webkit-mask: url("data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHdpZHRoPSIyNCIgaGVpZ2h0PSIyNCIgdmlld0JveD0iMCAwIDI0IDI0IiBmaWxsPSJub25lIiBzdHJva2U9ImN1cnJlbnRDb2xvciIgc3Ryb2tlLXdpZHRoPSIyIiBzdHJva2UtbGluZWNhcD0icm91bmQiIHN0cm9rZS1saW5lam9pbj0icm91bmQiPjxwYXRoIGQ9Im0yMSAxNi00IDQtNC00Ii8+PHBhdGggZD0iTTE3IDIwVjQiLz48cGF0aCBkPSJtMyA4IDQtNCA0IDgiLz48cGF0aCBkPSJNNyA0djE2Ii8+PC9zdmc+");
    mask-size: contain;
    mask-repeat: no-repeat;
    margin: 10px 0;
    transition: transform 0.3s ease;
}

input:focus ~ .icon-swap {
    transform: rotate(180deg);
}

/* Footer Section */


footer {
    position: fixed;
    bottom: 0;
    width: 100%;
    padding: 20px 0;
    background: rgba(15, 23, 42, 0.8);
    backdrop-filter: blur(10px);
    border-top: 1px solid #334155;
    text-align: center;
}

.footer-content p {
    color: #94a3b8;
    font-size: 0.85rem;
    margin-bottom: 8px;
}

.footer-links a {
    color: #38bdf8;
    text-decoration: none;
    font-size: 0.9rem;
    font-weight: 500;
    transition: color 0.2s;
}

.footer-links a:hover {
    color: #7dd3fc;
    text-decoration: underline;
}

.separator {
    color: #475569;
    margin: 0 10px;
}

.copyright {
    font-size: 0.75rem;
    opacity: 0.6;
    margin-top: 5px;
}