:root {
    --bg-color: #121212;
    --text-color: #e0e0e0;
    --glass-bg: rgba(255, 255, 255, 0.05);
    --glass-border: rgba(255, 255, 255, 0.1);
    --primary-color: #bb86fc;
    --secondary-color: #03dac6;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: 'Inter', sans-serif;
    margin: 0;
    padding: 0;
    min-height: 100vh;
    background-image:
        radial-gradient(circle at 10% 20%, rgba(94, 53, 177, 0.2) 0%, transparent 40%),
        radial-gradient(circle at 90% 80%, rgba(94, 53, 177, 0.1) 0%, transparent 40%);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

h1,
h2,
h3 {
    margin-top: 0;
}

a {
    color: var(--primary-color);
    text-decoration: none;
}

a:hover {
    text-decoration: underline;
}

/* Glassmorphism Card */
.glass-card {
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 1.5rem;
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
    margin-bottom: 2rem;
}

.problem-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 1.5rem;
}

.problem-card {
    transition: transform 0.2s, box-shadow 0.2s;
    cursor: pointer;
}

.problem-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
    background: rgba(255, 255, 255, 0.08);
}

.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
}

.btn {
    background: var(--primary-color);
    color: #000;
    padding: 0.5rem 1rem;
    border-radius: 8px;
    border: none;
    font-weight: bold;
    cursor: pointer;
    transition: background 0.2s;
}

.btn:hover {
    background: #a370f7;
    text-decoration: none;
}

/* Detail Page */
.code-viewer {
    margin-top: 1rem;
}

.tab-container {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1rem;
}

.tab {
    padding: 0.5rem 1rem;
    background: var(--glass-bg);
    border: 1px solid var(--glass-border);
    border-radius: 8px;
    cursor: pointer;
}

.tab.active {
    background: var(--primary-color);
    color: #000;
}

pre {
    background: rgba(0, 0, 0, 0.3) !important;
    border-radius: 8px;
    padding: 1rem !important;
    overflow-x: auto;
}

textarea {
    width: 100%;
    min-height: 200px;
    background: rgba(0, 0, 0, 0.3);
    border: 1px solid var(--glass-border);
    border-radius: 8px;
    color: var(--text-color);
    padding: 1rem;
    font-family: monospace;
    resize: vertical;
}

input[type="file"],
input[type="text"],
input[type="number"] {
    background: rgba(0, 0, 0, 0.3);
    border: 1px solid var(--glass-border);
    border-radius: 8px;
    color: var(--text-color);
    padding: 0.5rem;
    margin-bottom: 1rem;
    width: 100%;
}