:root {
    --primary-color: #0284c7;
    --primary-hover: #0369a1;
    --secondary-color: #e0f2fe;
    --text-color: #334155;
    --bg-color: #f8fafc;
    --card-bg: #ffffff;
    --border-color: #bae6fd;
    --error-color: #ef4444;
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    display: flex;
    flex-direction: column;
    align-items: center;
    min-height: 100vh;
}

header {
    width: 100%;
    background: linear-gradient(135deg, #0284c7, #38bdf8);
    color: white;
    padding: 1.5rem;
    text-align: center;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.05);
}

header h1 {
    font-size: 2rem;
    font-weight: 600;
}

main {
    flex: 1;
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100%;
    max-width: 800px;
    padding: 2rem;
}

.screen {
    width: 100%;
    display: none;
    animation: fadeIn 0.4s ease;
}

.screen.active {
    display: block;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(10px); }
    to { opacity: 1; transform: translateY(0); }
}

.card {
    background-color: var(--card-bg);
    border-radius: 12px;
    padding: 2rem;
    box-shadow: 0 8px 24px rgba(2, 132, 199, 0.08);
    border: 1px solid var(--border-color);
}

.form-group {
    margin-bottom: 1.5rem;
}

label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: #475569;
}

input[type="text"],
input[type="number"],
select {
    width: 100%;
    padding: 0.8rem;
    border: 1px solid #cbd5e1;
    border-radius: 6px;
    font-size: 1rem;
    transition: all 0.2s;
    color: #334155;
}

input:focus, select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(2, 132, 199, 0.2);
}

.error {
    color: var(--error-color);
    font-size: 0.85rem;
    margin-top: 0.5rem;
    font-weight: 500;
}

.hidden {
    display: none !important;
}

button {
    cursor: pointer;
    border: none;
    border-radius: 6px;
    padding: 0.8rem 1.5rem;
    font-size: 1rem;
    font-weight: 600;
    transition: all 0.2s;
    width: 100%;
}

.primary-btn {
    background-color: var(--primary-color);
    color: white;
}

.primary-btn:hover {
    background-color: var(--primary-hover);
    transform: translateY(-1px);
}

.secondary-btn {
    background-color: var(--secondary-color);
    color: var(--primary-color);
}

.secondary-btn:hover {
    background-color: #bae6fd;
}

.twitter-btn {
    background-color: #0f1419;
    color: white;
}

.twitter-btn:hover {
    background-color: #272c30;
}

.question-box {
    text-align: center;
    background-color: #f8fafc;
    padding: 2rem;
    border-radius: 8px;
    border: 2px dashed #7dd3fc;
    margin-bottom: 1.5rem;
    margin-top: 1rem;
}

.binary-label {
    font-size: 0.9rem;
    color: #64748b;
    margin-bottom: 0.5rem;
}

.binary-text {
    font-size: 3rem;
    font-weight: bold;
    letter-spacing: 6px;
    color: var(--primary-color);
}

.result-container {
    display: flex;
    gap: 2rem;
}

.result-left, .result-right {
    flex: 1;
}

.result-left {
    text-align: center;
}

.score-display {
    font-size: 2.5rem;
    font-weight: bold;
    color: var(--primary-color);
    margin: 1.5rem 0;
}

.action-buttons {
    display: flex;
    flex-direction: column;
    gap: 0.8rem;
}

.ranking-list {
    list-style: none;
    margin-top: 1rem;
}

.ranking-list li {
    background-color: #f8fafc;
    padding: 1rem;
    margin-bottom: 0.8rem;
    border-radius: 6px;
    border-left: 4px solid var(--primary-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 2px 4px rgba(0,0,0,0.02);
}

.ranking-rank {
    font-weight: bold;
    color: var(--primary-color);
    margin-right: 1rem;
}

.ranking-score {
    font-weight: bold;
    font-size: 1.2rem;
}

#question-number {
    color: #475569;
    text-align: center;
}

.mt-2 {
    margin-top: 2rem;
}

.global-ranking-container {
    display: flex;
    gap: 1.5rem;
    width: 100%;
}

.global-ranking-col {
    flex: 1;
    padding: 1.5rem;
}

.ranking-title {
    font-size: 1.1rem;
    color: var(--primary-color);
    text-align: center;
    margin-bottom: 1rem;
    border-bottom: 2px solid var(--secondary-color);
    padding-bottom: 0.5rem;
}

.global-ranking-col .ranking-list li {
    padding: 0.8rem;
    font-size: 0.9rem;
}

@media (max-width: 768px) {
    .result-container, .global-ranking-container {
        flex-direction: column;
    }
}