:root {
    --bg-primary: #0a0a1a;
    --bg-secondary: rgba(20, 20, 50, 0.6);
    --glass-bg: rgba(255, 255, 255, 0.03);
    --glass-border: rgba(255, 255, 255, 0.1);
    --accent: #ff4d6d;
    --accent2: #c77dff;
    --accent3: #7209b7;
    --text: #ffffff;
    --text-dim: rgba(255, 255, 255, 0.6);
    --shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
    --radius: 20px;
    --transition: 0.2s ease;
}

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

body {
    font-family: 'Plus Jakarta Sans', sans-serif;
    background: var(--bg-primary);
    color: var(--text);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 20px;
    overflow-x: hidden;
    position: relative;
}

.bg-gradient {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: 
        radial-gradient(circle at 20% 20%, rgba(199, 125, 255, 0.15), transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(255, 77, 109, 0.1), transparent 50%);
    pointer-events: none;
    z-index: 0;
}

.container {
    position: relative;
    z-index: 1;
    width: 100%;
    max-width: 420px;
}

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

.logo-group {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
}

.logo-icon {
    font-size: 2.5rem;
    animation: float 3s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-8px); }
}

.logo {
    font-size: 2.4rem;
    font-weight: 800;
    letter-spacing: -1px;
}

.accent {
    background: linear-gradient(135deg, var(--accent), var(--accent2));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    color: var(--text-dim);
    margin-top: 0.4rem;
    font-size: 0.95rem;
}

/* Glass card */
.glass {
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.calc-card {
    padding: 1.5rem;
    margin-bottom: 1.5rem;
}

.display-area {
    margin-bottom: 1.2rem;
}

.calc-input {
    width: 100%;
    padding: 1rem 1.2rem;
    font-size: 1.8rem;
    font-weight: 600;
    text-align: right;
    background: rgba(255, 255, 255, 0.05);
    border: 2px solid rgba(255, 255, 255, 0.15);
    border-radius: 14px;
    color: var(--text);
    outline: none;
    transition: var(--transition);
    font-family: 'Courier New', monospace;
}

.calc-input:focus {
    border-color: var(--accent2);
    box-shadow: 0 0 20px rgba(199, 125, 255, 0.3);
}

.calc-input::placeholder {
    color: rgba(255, 255, 255, 0.25);
    font-size: 1rem;
    font-family: 'Plus Jakarta Sans', sans-serif;
}

.button-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 0.7rem;
}

.btn {
    padding: 1rem;
    font-size: 1.3rem;
    font-weight: 600;
    border: none;
    border-radius: 14px;
    cursor: pointer;
    transition: var(--transition);
    color: var(--text);
    position: relative;
    overflow: hidden;
}

.num {
    background: rgba(255, 255, 255, 0.06);
}

.num:hover {
    background: rgba(255, 255, 255, 0.12);
    transform: translateY(-2px);
}

.op {
    background: rgba(199, 125, 255, 0.2);
    color: var(--accent2);
}

.op:hover {
    background: rgba(199, 125, 255, 0.3);
}

.clear {
    background: rgba(255, 77, 109, 0.2);
    color: var(--accent);
}

.clear:hover {
    background: rgba(255, 77, 109, 0.4);
}

.equals {
    grid-column: span 4;
    background: linear-gradient(135deg, var(--accent), var(--accent3));
    font-size: 1.6rem;
    font-weight: 700;
    box-shadow: 0 4px 15px rgba(255, 77, 109, 0.4);
}

.equals:hover {
    box-shadow: 0 6px 20px rgba(255, 77, 109, 0.6);
    transform: translateY(-2px);
}

.btn:active {
    transform: scale(0.96);
}

/* Response card */
.response-card {
    padding: 1.4rem;
    min-height: 80px;
    margin-bottom: 1.5rem;
}

.loading-state {
    display: none;
    text-align: center;
    padding: 1rem 0;
}

.spinner {
    width: 36px;
    height: 36px;
    border: 3px solid rgba(255, 255, 255, 0.1);
    border-top-color: var(--accent2);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
    margin: 0 auto 0.8rem;
}

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

.result-content {
    animation: fadeInUp 0.4s ease;
}

@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(12px); }
    to { opacity: 1; transform: translateY(0); }
}

.savage-text {
    font-size: 1rem;
    line-height: 1.6;
    margin-bottom: 0.8rem;
}

.answer-text {
    font-size: 1.8rem;
    font-weight: 700;
    background: linear-gradient(135deg, var(--accent), var(--accent2));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.error-text {
    color: #ff6b6b;
}

.ai-badge {
    display: inline-block;
    padding: 0.25rem 0.7rem;
    background: rgba(199, 125, 255, 0.15);
    border-radius: 30px;
    font-size: 0.7rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-top: 0.8rem;
}

footer {
    text-align: center;
    font-size: 0.8rem;
    color: var(--text-dim);
}

@media (max-width: 480px) {
    .btn {
        padding: 0.8rem;
        font-size: 1.1rem;
    }
    .calc-input {
        font-size: 1.4rem;
    }
}