* {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: system-ui, sans-serif;
    background: radial-gradient(circle at top, #020617, #000);
    color: #e5e7eb;
}

/* Header */
header {
    backdrop-filter: blur(12px);
    background: rgba(2, 6, 23, 0.6);
    padding: 20px;
    text-align: center;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}

nav {
    display: flex;
    justify-content: center;
    gap: 10px;
    flex-wrap: wrap;
}

nav button {
    background: rgba(30,41,59,0.6);
    border: 1px solid rgba(255,255,255,0.1);
    color: #e5e7eb;
    padding: 10px 16px;
    border-radius: 10px;
    cursor: pointer;
    backdrop-filter: blur(8px);
    transition: all 0.3s ease;
}

nav button:hover {
    background: rgba(56,189,248,0.3);
    color: #38bdf8;
}

/* Main */
main {
    max-width: 900px;
    margin: auto;
    padding: 30px;
    min-height: 60vh;
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.35s ease, transform 0.35s ease;
}

main.show {
    opacity: 1;
    transform: translateY(0);
}

/* Glass Cards */
.glass {
    background: rgba(2,6,23,0.55);
    backdrop-filter: blur(14px);
    border: 1px solid rgba(255,255,255,0.12);
    border-radius: 16px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.6);
}

.card {
    padding: 20px;
    margin-bottom: 20px;
    animation: cardEnter 0.5s ease forwards;
}

@keyframes cardEnter {
    from {
        opacity: 0;
        transform: translateY(25px) scale(0.97);
    }
    to {
        opacity: 1;
        transform: translateY(0) scale(1);
    }
}

.card h2, .card h3 {
    color: #38bdf8;
}

.card:hover {
    box-shadow: 0 0 25px rgba(56,189,248,0.25);
    transform: translateY(-3px);
    transition: all 0.3s ease;
}

.timer {
    font-size: 1.6rem;
    font-weight: bold;
    letter-spacing: 1px;
}

/* Footer */
footer {
    text-align: center;
    padding: 15px;
    font-size: 14px;
    color: #94a3b8;
    background: rgba(2,6,23,0.5);
}

/* Mobile */
@media (max-width: 600px) {
    .timer {
        font-size: 1.3rem;
    }
}