:root {
    --primary: #007AFF;
    --primary-hover: #0063CC;
    --background: #000000;
    --surface: #1C1C1E;
    --text-primary: #FFFFFF;
    --text-secondary: #86868B;
    --glass: rgba(255, 255, 255, 0.05);
    --golden-ratio: 1.618;
    --base-unit: 1rem;
    --sf-font: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'SF Pro Text', 'Inter', sans-serif;
    --ease-squish: cubic-bezier(0.65, 0, 0.35, 1);
    --ease-glass: cubic-bezier(0.68, -0.55, 0.27, 1.55);
    --depth-1: 0 1px 2px rgba(0,0,0,0.02);
    --depth-2: 0 4px 12px rgba(0,0,0,0.08);
    --depth-3: 0 12px 32px rgba(0,0,0,0.12);
}

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

body {
    font-family: var(--sf-font);
    background: var(--background);
    color: var(--text-primary);
    min-height: 100vh;
    display: grid;
    place-items: center;
    overflow: hidden;
    text-rendering: optimizeLegibility;
    -webkit-font-smoothing: antialiased;
}

.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--background);
    z-index: 9999;
    display: grid;
    place-items: center;
    transition: opacity 0.6s ease;
}

.loading-spinner {
    width: 48px;
    height: 48px;
    border: 3px solid var(--text-secondary);
    border-radius: 50%;
    border-top-color: var(--primary);
    animation: spin 1s linear infinite;
}

.glass-container {
    width: 90vw;
    max-width: 440px;
    min-height: 80vh;
    aspect-ratio: 1/var(--golden-ratio);
    margin: 2rem auto;
    backdrop-filter: blur(40px);
    background: var(--glass);
    border-radius: 2rem;
    border: 1px solid rgba(255, 255, 255, 0.1);
    box-shadow: var(--depth-3);
    position: relative;
    overflow: hidden;
    transform: perspective(1000px);
    transform-style: preserve-3d;
    animation: container-entrance 1.2s var(--ease-squish) forwards;
    opacity: 0;
}

.app-nav {
    position: absolute;
    top: 1.5rem;
    right: 1.5rem;
    display: flex;
    gap: 0.75rem;
    z-index: 10;
}

.nav-button {
    width: 40px;
    height: 40px;
    border-radius: 12px;
    background: var(--surface);
    border: none;
    color: var(--text-primary);
    display: grid;
    place-items: center;
    cursor: pointer;
    transition: all 0.3s var(--ease-squish);
    backdrop-filter: blur(20px);
    box-shadow: var(--depth-2);
    position: relative;
    overflow: hidden;
}

.nav-button:hover {
    transform: scale(1.08);
    background: var(--primary);
}

.nav-button:hover::after {
    content: '';
    position: absolute;
    width: 100%;
    height: 100%;
    background: radial-gradient(circle at center, 
        var(--primary) 0%, 
        transparent 70%);
    animation: quantum-pulse 0.6s var(--ease-glass);
}

.calculator {
    padding: 2.5rem;
    position: relative;
    z-index: 2;
    display: flex;
    flex-direction: column;
    height: 100%;
}

.app-title {
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 2.5rem;
    text-align: center;
}

.title-gradient {
    background: linear-gradient(45deg, #7B61FF, #FF61E5);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    display: inline-block;
}

.input-group {
    margin-bottom: 1.5rem;
    flex: 1;
}

.input-group label {
    display: block;
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
    font-weight: 500;
}

.input-field {
    position: relative;
    display: flex;
    align-items: center;
    background: var(--surface);
    border-radius: 1rem;
    padding: 0.5rem 1rem;
    transition: all 0.6s var(--ease-squish), box-shadow 0.3s ease;
    transform-origin: center bottom;
}

.input-field:hover {
    transform: translateY(-4px) scale(1.02);
    box-shadow: var(--depth-3);
}

.input-field input {
    flex: 1;
    border: none;
    background: transparent;
    color: var(--text-primary);
    font-size: 1.1rem;
    padding: 0.75rem 0;
    font-weight: 500;
    transition: transform 0.3s var(--ease-squish);
}

.input-field input:focus {
    transform: scale(1.03);
}

.input-field .material-symbols-rounded {
    color: var(--text-secondary);
    margin-right: 0.75rem;
    font-size: 1.5rem;
}

.result-card {
    background: var(--surface);
    border-radius: 1rem;
    padding: 1.5rem;
    text-align: center;
    position: relative;
    overflow: hidden;
    animation: card-appear 0.6s var(--ease-squish);
}

.result-card::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(
        45deg,
        rgba(255,255,255,0.1) 0%,
        rgba(255,255,255,0) 30%,
        rgba(255,255,255,0.1) 70%,
        rgba(255,255,255,0) 100%
    );
    animation: holographic-glow 6s linear infinite;
    mask: linear-gradient(transparent 20%, white 90%);
}

.result-label {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
}

.result-value {
    font-size: 2rem;
    font-weight: 700;
    color: var(--text-primary);
    transition: all 0.3s ease;
}

.fab-menu {
    position: absolute;
    bottom: 2rem;
    right: 2rem;
    z-index: 100;
}

.fab-main {
    width: 56px;
    height: 56px;
    border-radius: 16px;
    background: var(--primary);
    border: none;
    color: white;
    display: grid;
    place-items: center;
    cursor: pointer;
    transition: all 0.3s var(--ease-squish);
    box-shadow: var(--depth-3);
}

.fab-items {
    position: absolute;
    bottom: 70px;
    right: 0;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
    opacity: 0;
    transform: translateY(20px);
    transition: all 0.3s ease;
}

.fab-item {
    padding: 12px 20px;
    background: var(--surface);
    border-radius: 12px;
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
    transition: all 0.3s ease;
    backdrop-filter: blur(20px);
    box-shadow: var(--depth-2);
}

.fab-menu.active .fab-item {
    animation: fab-emerge 0.6s var(--ease-squish) backwards;
}

.fab-item:hover {
    background: var(--primary);
    transform: translateX(-10px);
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

@keyframes container-entrance {
    0% { opacity: 0; transform: scale(0.98) rotateX(5deg); }
    100% { opacity: 1; transform: scale(1) rotateX(0); }
}

@keyframes card-appear {
    0% { opacity: 0; transform: translateY(20px); }
    100% { opacity: 1; transform: translateY(0); }
}

@keyframes holographic-glow {
    0% { opacity: 0.3; transform: translateX(-100%); }
    100% { opacity: 0.3; transform: translateX(100%); }
}

@keyframes quantum-pulse {
    0% { transform: scale(0); opacity: 1; }
    100% { transform: scale(2); opacity: 0; }
}

@keyframes fab-emerge {
    0% { opacity: 0; transform: translateY(20px) rotateX(45deg); }
}

@media (max-width: 480px) {
    .glass-container {
        width: 95vw;
        margin: 1rem auto;
    }
    
    .calculator {
        padding: 1.5rem;
    }
    
    .app-title {
        font-size: 1.5rem;
    }
    
    .fab-menu {
        bottom: 1.5rem;
        right: 1.5rem;
    }
}