:root {
    --bg: #111116;
    --surface: #1A1A22;
    --border: rgba(99, 102, 241, .15);
    --border-focus: #6366F1;
    --text: #E4E4F0;
    --text2: #8B8BA0;
    --text3: #4B4B60;
    --primary: #6366F1;
    --primary-hover: #5558E0;
    --glow: rgba(99, 102, 241, .2);
    --sans: 'Inter', system-ui, sans-serif;
    --mono: 'JetBrains Mono', monospace;
    --r: 12px;
    --rs: 8px;
    --t: 200ms ease
}

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

html {
    font-size: 15px;
    -webkit-font-smoothing: antialiased
}

body {
    font-family: var(--sans);
    background: var(--bg);
    color: var(--text);
    min-height: 100vh
}

.app-header {
    background: var(--surface);
    border-bottom: 1px solid var(--border)
}

.header-inner {
    max-width: 640px;
    margin: 0 auto;
    padding: 0 24px;
    height: 56px;
    display: flex;
    align-items: center
}

.header-inner h1 {
    font-size: 1.05rem;
    font-weight: 700
}

.app-main {
    max-width: 640px;
    margin: 0 auto;
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 20px
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 9px 18px;
    border-radius: var(--rs);
    font-family: var(--sans);
    font-size: .87rem;
    font-weight: 600;
    border: none;
    cursor: pointer;
    transition: all var(--t)
}

.btn-ghost {
    background: transparent;
    color: var(--text2)
}

.btn-ghost:hover {
    color: var(--text)
}

.btn-sm {
    padding: 5px 10px;
    font-size: .78rem
}

.converter-card,
.reference-card {
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--r);
    padding: 24px
}

.direction-toggle {
    display: flex;
    gap: 4px;
    background: var(--bg);
    border-radius: var(--rs);
    padding: 3px;
    margin-bottom: 16px
}

.dir-btn {
    flex: 1;
    padding: 8px;
    border: none;
    border-radius: 6px;
    font-family: var(--sans);
    font-size: .82rem;
    font-weight: 600;
    color: var(--text3);
    background: transparent;
    cursor: pointer;
    transition: all var(--t)
}

.dir-btn.active {
    background: var(--primary);
    color: #fff
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: 6px
}

.input-group label {
    font-size: .72rem;
    font-weight: 600;
    color: var(--text3);
    text-transform: uppercase;
    letter-spacing: .5px
}

.input-group input {
    padding: 14px 16px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--rs);
    font-family: var(--mono);
    font-size: 1.1rem;
    font-weight: 500;
    color: var(--text);
    transition: border-color var(--t)
}

.input-group input:focus {
    outline: none;
    border-color: var(--border-focus);
    box-shadow: 0 0 0 3px var(--glow)
}

.result-group {
    margin-top: 16px;
    display: flex;
    flex-direction: column;
    gap: 8px;
    align-items: flex-start
}

.result-label {
    font-size: .72rem;
    font-weight: 600;
    color: var(--text3);
    text-transform: uppercase
}

.result-val {
    font-family: var(--mono);
    font-size: 1.6rem;
    font-weight: 700;
    color: var(--primary);
    word-break: break-all;
    line-height: 1.3
}

.error-msg {
    margin-top: 12px;
    padding: 10px 14px;
    background: rgba(239, 68, 68, .08);
    border: 1px solid rgba(239, 68, 68, .2);
    border-radius: var(--rs);
    font-size: .85rem;
    color: #EF4444
}

.reference-card h2 {
    font-size: .82rem;
    font-weight: 700;
    margin-bottom: 12px
}

.ref-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(90px, 1fr));
    gap: 6px
}

.ref-item {
    display: flex;
    justify-content: space-between;
    padding: 6px 10px;
    background: var(--bg);
    border-radius: 6px;
    font-size: .8rem;
    font-family: var(--mono)
}

.ref-item .ri-num {
    color: var(--text3)
}

.ref-item .ri-rom {
    color: var(--primary);
    font-weight: 600
}

.toast {
    position: fixed;
    bottom: 24px;
    left: 50%;
    transform: translateX(-50%);
    padding: 10px 24px;
    background: var(--primary);
    color: #fff;
    border-radius: var(--rs);
    font-size: .87rem;
    font-weight: 600;
    box-shadow: 0 4px 24px var(--glow);
    z-index: 200;
    animation: ts .3s ease
}

@keyframes ts {
    from {
        opacity: 0;
        transform: translateX(-50%) translateY(8px)
    }

    to {
        opacity: 1;
        transform: translateX(-50%) translateY(0)
    }
}

@media(max-width:500px) {
    .app-main {
        padding: 16px
    }

    .result-val {
        font-size: 1.2rem
    }
}