:root {
    --bg-color: #0f172a;
    --card-bg: rgba(30, 41, 59, 0.7);
    --accent-color: #8b5cf6;
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --glass-border: rgba(255, 255, 255, 0.1);
    --font-family: 'Inter', system-ui, -apple-system, sans-serif;
}

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

body {
    background: radial-gradient(circle at top left, #1e1b4b, #0f172a);
    color: var(--text-primary);
    font-family: var(--font-family);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 2rem;
}

header {
    text-align: center;
    margin-bottom: 3rem;
}

header h1 {
    font-size: 2.5rem;
    font-weight: 800;
    background: linear-gradient(to right, #a78bfa, #f472b6);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 0.5rem;
}

header p {
    color: var(--text-secondary);
}

.controls {
    width: 100%;
    max-width: 600px;
    margin-bottom: 3rem;
    display: flex;
    gap: 1rem;
}

select, input {
    flex: 1;
    background: var(--card-bg);
    border: 1px solid var(--glass-border);
    padding: 0.75rem 1rem;
    border-radius: 12px;
    color: var(--text-primary);
    font-size: 1rem;
    outline: none;
    backdrop-filter: blur(12px);
}

button {
    background: var(--accent-color);
    color: white;
    border: none;
    padding: 0.75rem 1.5rem;
    border-radius: 12px;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.2s, background 0.2s;
}

button:hover {
    background: #7c3aed;
    transform: translateY(-2px);
}

.clock-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 2rem;
    width: 100%;
    max-width: 1200px;
}

.clock-card {
    background: var(--card-bg);
    backdrop-filter: blur(16px);
    border: 1px solid var(--glass-border);
    border-radius: 24px;
    padding: 2rem;
    position: relative;
    overflow: hidden;
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.clock-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 25px -5px rgba(0, 0, 0, 0.2);
}

.clock-card .remove-btn {
    position: absolute;
    top: 1rem;
    right: 1rem;
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 0.5rem;
    border-radius: 50%;
    transition: background 0.2s, color 0.2s;
}

.clock-card .remove-btn:hover {
    background: rgba(239, 68, 68, 0.2);
    color: #ef4444;
}

.city-name {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.timezone-label {
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

.time-display {
    font-size: 3rem;
    font-weight: 800;
    font-variant-numeric: tabular-nums;
    margin-bottom: 0.5rem;
}

.date-display {
    font-size: 1rem;
    color: var(--text-secondary);
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.clock-card {
    animation: fadeIn 0.5s ease-out forwards;
}