:root {
    --bg-color: #0f172a;
    --card-bg: rgba(30, 41, 59, 0.7);
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --accent-color: #38bdf8;
    --accent-glow: rgba(56, 189, 248, 0.3);
    --input-bg: rgba(15, 23, 42, 0.6);
    --border-color: rgba(148, 163, 184, 0.2);
    --font-family: 'Outfit', sans-serif;
}

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

body {
    font-family: var(--font-family);
    background-color: var(--bg-color);
    color: var(--text-primary);
    min-height: 100vh;
    padding: 20px;
    position: relative;
    /* display: flex; override for sidebar */
}

.main-container {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: calc(100vh - 40px);
    width: 100%;
}

.background-glow {
    position: absolute;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, var(--accent-glow) 0%, transparent 70%);
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    z-index: -1;
    pointer-events: none;
}

.calculator-card {
    background: var(--card-bg);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border: 1px solid var(--border-color);
    border-radius: 24px;
    padding: 2.5rem;
    width: 100%;
    max-width: 400px;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    animation: fadeIn 0.6s ease-out;
}

header {
    text-align: center;
    margin-bottom: 2rem;
}

header h1 {
    font-weight: 600;
    font-size: 1.8rem;
    letter-spacing: -0.02em;
    margin-bottom: 0.25rem;
}

header p {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.input-group {
    margin-bottom: 1.5rem;
}

.input-group label {
    display: block;
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
    background: var(--input-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    transition: all 0.3s ease;
}

.input-wrapper:focus-within {
    border-color: var(--accent-color);
    box-shadow: 0 0 0 4px var(--accent-glow);
}

.input-wrapper.readonly {
    background: rgba(15, 23, 42, 0.3);
    border-color: transparent;
}

.currency-symbol {
    padding-left: 1rem;
    color: var(--text-secondary);
    font-weight: 300;
}

input {
    width: 100%;
    background: transparent;
    border: none;
    color: var(--text-primary);
    font-family: var(--font-family);
    font-size: 1.25rem;
    padding: 1rem;
    outline: none;
    text-align: right;
    font-weight: 600;
}

input::placeholder {
    color: rgba(148, 163, 184, 0.4);
}

.btn-reset {
    width: 100%;
    padding: 1rem;
    background: linear-gradient(135deg, var(--accent-color), #0ea5e9);
    border: none;
    border-radius: 12px;
    color: white;
    font-family: var(--font-family);
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: transform 0.2s, box-shadow 0.2s;
    margin-top: 1rem;
}

.btn-reset:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px -5px var(--accent-glow);
}

.btn-reset:active {
    transform: translateY(0);
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@media (max-width: 480px) {
    .calculator-card {
        padding: 1.5rem;
        border-radius: 20px;
    }
}