:root {
    --primary-color: #0f172a;       /* deep navy */
    --secondary-color: #14b8a6;     /* teal professional accent */
    --background-color: #020617;    /* dark background */
    --text-color: #e2e8f0;          /* soft white */
    --card-hover-bg: #1e293b;       /* elevated navy */
    --button-hover-bg: #0ea5e9;     /* sky accent hover */
}

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

body {
    font-family: 'Roboto', sans-serif;
    background-color: var(--background-color);
    color: var(--text-color);
    line-height: 1.6;
}

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

header {
    background-color: var(--primary-color);
    color: white;
    text-align: center;
    padding: 2rem 0;
    position: relative;
}

h1 {
    font-size: 2.5rem;
    margin-bottom: 0.5rem;
}

.subtitle {
    font-size: 1.2rem;
    font-weight: 300;
}

main {
    padding: 2rem 0;
}

h2 {
    text-align: center;
    margin-bottom: 2rem;
    color: var(--secondary-color);
}

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

.search-input {
    padding: 0.5rem;
    font-size: 1rem;
    border: 1px solid var(--secondary-color);
    border-radius: 4px;
    background-color: var(--primary-color);
    color: var(--text-color);
}

.search-input:hover {
    box-shadow: 0 0 9px var(--secondary-color);
}

.search-button {
    padding: 0.5rem 1rem;
    font-size: 1rem;
    background-color: var(--secondary-color);
    color: var(--text-color);
    border: none;
    border-radius: 4px;
    cursor: pointer;
    margin-left: 0.5rem;
}

.search-button:hover {
    background-color: var(--button-hover-bg);
    color: #fff;
    box-shadow: 0 0 12px var(--secondary-color);
}

.assignments {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.assignment {
    background: linear-gradient(135deg, #2c3e50, #4ca1af);
    border-radius: 10px;
    padding: 1.5rem;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
    transition: transform 0.3s ease, background-color 0.3s ease;
}

.assignment:hover {
    transform: translateY(-4px);
    background: var(--card-hover-bg);
    box-shadow: 0 0 20px var(--secondary-color);
}

.assignment-content {
    text-align: center;
}

.assignment-title {
    font-size: 1.2rem;
    font-weight: bold;
    margin-bottom: 1rem;
    color: var(--text-color);
}

.view-button {
    display: inline-block;
    background-color: var(--secondary-color);
    color: #fff;
    padding: 0.5rem 1rem;
    text-decoration: none;
    border-radius: 4px;
    transition: background-color 0.3s ease;
}

.view-button:hover {
    background-color: var(--button-hover-bg);
    box-shadow: 0 0 12px var(--secondary-color);
    color: #f1f8f1;
}

/* Hidden Search Result */
.hidden {
    display: none;
}

/* Right Top Icon */
.icon-container {
    position: absolute;
    top: .5rem;
    right: .5rem;
    display: flex;
    gap: 1rem;
    font-size: 2.2rem;
}

.icon {
    color: #fff;
}

.icon:hover {
    color: var(--secondary-color);
    box-shadow: 0 0 10px var(--secondary-color);
    border-radius: 50%;
    transition: color 0.3s ease;
}

/* Responsive */
@media screen and (max-width: 430px) {
    .container {
        padding: 1rem;
    }

    h1 {
        font-size: 2rem;
    }

    .subtitle {
        font-size: 1rem;
    }

    h2 {
        font-size: 1.5rem;
    }

    .assignments {
        grid-template-columns: 1fr;
    }

    .assignment {
        margin-bottom: 1.5rem;
    }

    .assignment-title {
        font-size: 1rem;
    }

    .view-button {
        padding: 0.4rem 0.8rem;
        font-size: 0.9rem;
    }

    .search-input,
    .search-button {
        width: 100%;
        margin-bottom: 0.5rem;
    }

    .icon-container {
        font-size: 1.8rem;
    }
}