* {
    box-sizing: border-box;
}
html, body {
    height: 100%;
    margin: 0;
    display: flex;
    flex-direction: column;
}
main {
    flex: 1;
}
body {
    margin: 0;
    font-family: 'Roboto', sans-serif;
    background-color: #0a0f1a;
    color: #d0eaff;
    overflow-x: hidden;
}
header {
    text-align: center;
    padding: 2rem 1rem;
    background: linear-gradient(90deg, #0a192f, #112240, #0a192f);
    border-bottom: 1px solid #1f4068;
}
header h1 {
    font-family: 'Orbitron', sans-serif;
    font-size: 2.5rem;
    color: #00d4ff;
    margin: 0;
    text-shadow: 0 0 10px #00d4ff;
}
header p {
    color: #8ab4f8;
    font-size: 1rem;
    letter-spacing: 1px;
    margin-top: 0.5rem;
}
#controls {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    margin: 1.5rem auto;
    max-width: 800px;
}
#search {
    flex: 1;
    padding: 0.7rem 1rem;
    background: #111a2b;
    border: 1px solid #00d4ff;
    color: #d0eaff;
    border-radius: 8px;
    font-size: 1rem;
    transition: box-shadow 0.3s;
}
#search:focus {
    outline: none;
    box-shadow: 0 0 10px #00d4ff80;
}
#reload {
    background: #00d4ff;
    color: #0a0f1a;
    border: none;
    padding: 0.7rem 1.2rem;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
}
#reload:hover {
    background: #0ff;
    transform: scale(1.05);
}
#problems-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 1.5rem;
    padding: 1rem;
    max-width: 1200px;
    margin: 0 auto;
}
.problem-card {
    background: #101825;
    border: 1px solid #112d4e;
    border-left: 4px solid #00d4ff;
    border-radius: 12px;
    padding: 1rem 1.2rem;
    box-shadow: 0 0 15px rgba(0, 212, 255, 0.05);
    transition: transform 0.25s ease, box-shadow 0.3s;
    cursor: pointer;
}
.problem-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 0 15px rgba(0, 212, 255, 0.3);
}
.problem-card h2 {
    color: #00d4ff;
    font-family: 'Orbitron', sans-serif;
    font-size: 1.3rem;
    margin-top: 0;
}
.problem-card p {
    color: #bcd4ff;
    line-height: 1.4;
}
/* Modal */

#modal-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.75);
    justify-content: center;
    align-items: center;
    z-index: 1000;
}
#modal {
    background: #0b1422;
    border: 1px solid #00d4ff;
    border-radius: 12px;
    padding: 1.5rem;
    width: 90%;
    max-width: 600px;
    color: #d0eaff;
    position: relative;
    animation: popUp 0.4s ease;
}
#close-modal {
    position: absolute;
    top: 10px;
    right: 15px;
    cursor: pointer;
    font-size: 1.4rem;
    color: #00d4ff;
}
#modal h2 {
    font-family: 'Orbitron', sans-serif;
    color: #00d4ff;
}
#modal h3 {
    color: #8ab4f8;
    margin-top: 1rem;
    margin-bottom: 0.3rem;
}
#modal p {
    color: #bcd4ff;
    line-height: 1.5;
}
@keyframes popUp {
    from {
        transform: scale(0.8);
        opacity: 0;
    }
    to {
        transform: scale(1);
        opacity: 1;
    }
}
footer {
    text-align: center;
    padding: 1rem;
    background: #0a192f;
    color: #5fa8d3;
    border-top: 1px solid #1f4068;
    margin-top: auto;
}
footer .creator {
    margin: 0.25rem 0 0;
    color: #9ad4ff;
    font-size: 0.92rem;
    opacity: 0.95;
}
footer .creator-name {
    color: #00d4ff;
    font-weight: 700;
    letter-spacing: 0.6px;
}
.loading {
    text-align: center;
    color: #8ab4f8;
}