body {
    font-family: "Segoe UI", sans-serif;
    background: #0f172a;
    color: #e2e8f0;
    margin: 0;
    line-height: 1.6;
}

header {
    background: #1e293b;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid #334155;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: #38bdf8;
    text-decoration: none;
}

nav a {
    color: #cbd5e1;
    text-decoration: none;
    margin-left: 1.5rem;
    transition: color 0.3s;
}

nav a:hover {
    color: #38bdf8;
}

.hero {
    text-align: center;
    padding: 4rem 1rem;
}

h1 {
    font-size: 3rem;
    margin-bottom: 1rem;
    color: #f8fafc;
}

.btn {
    display: inline-block;
    background: #38bdf8;
    color: #0f172a;
    padding: 0.8rem 1.5rem;
    border-radius: 6px;
    text-decoration: none;
    font-weight: bold;
    margin-top: 1rem;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 2rem;
}

.card {
    background: #1e293b;
    padding: 2rem;
    border-radius: 8px;
    margin-bottom: 1.5rem;
    border: 1px solid #334155;
}

.quiz-box {
    background: #0f172a;
    padding: 1rem;
    border-radius: 4px;
    margin-top: 1rem;
    cursor: pointer;
    border: 1px solid #334155;
}

.quiz-box:hover {
    border-color: #38bdf8;
}

.answer {
    display: none;
    margin-top: 0.5rem;
    font-weight: bold;
}

.human {
    color: #4ade80;
}

.ai {
    color: #f472b6;
}

.progress-container {
    background: #1e293b;
    height: 10px;
    width: 100%;
    position: sticky;
    top: 0;
}

.progress-bar {
    width: 100%;
    height: 100%;
}

#progress-fill {
    height: 100%;
    background: #38bdf8;
    transition: width 0.5s ease;
}

.card.completed {
    border-color: #22c55e;
    opacity: 0.6;
}

.card.completed .status {
    color: #22c55e;
}

.status {
    font-size: 0.8rem;
    font-weight: bold;
    letter-spacing: 1px;
    color: #94a3b8;
}

.option {
    display: block;
    width: 100%;
    padding: 1rem;
    margin: 0.5rem 0;
    background: #0f172a;
    border: 1px solid #334155;
    color: #fff;
    text-align: left;
    cursor: pointer;
    border-radius: 6px;
}

.option:hover {
    background: #1e293b;
}

.feedback {
    display: none;
    margin-top: 10px;
    font-weight: bold;
}

.divider {
    border: 0;
    border-top: 1px solid #334155;
    margin: 3rem 0;
}