:root {
    --primary-color: #ffd700;
    --secondary-color: #1a2a3a;
    --text-color: #ffffff;
    --bg-color: #0f172a;
    --card-bg: #1e293b;
    --accent-color: #38bdf8;
    --danger-color: #ef4444;
}

* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    display: flex;
    justify-content: center;
    min-height: 100vh;
}

#app {
    width: 100%;
    max-width: 480px; /* Mobile width */
    background-color: var(--secondary-color);
    min-height: 100vh;
    position: relative;
    overflow-x: hidden;
    box-shadow: 0 0 20px rgba(0,0,0,0.5);
}

.screen {
    padding: 20px;
    display: none;
    flex-direction: column;
    height: 100vh;
    overflow-y: auto;
}

.screen.active {
    display: flex;
}

/* Typography */
h1 {
    font-size: 24px;
    margin-bottom: 20px;
    color: var(--primary-color);
    text-align: center;
}

h2 {
    font-size: 18px;
    margin-bottom: 15px;
    color: var(--accent-color);
}

p {
    line-height: 1.6;
    margin-bottom: 15px;
    font-size: 14px;
    color: #cbd5e1;
}

/* Buttons */
.btn {
    background-color: var(--primary-color);
    color: var(--secondary-color);
    border: none;
    padding: 12px 24px;
    border-radius: 8px;
    font-weight: bold;
    font-size: 16px;
    cursor: pointer;
    width: 100%;
    margin-top: auto;
    transition: transform 0.1s;
}

.btn:active {
    transform: scale(0.98);
}

.btn-secondary {
    background-color: transparent;
    border: 2px solid var(--primary-color);
    color: var(--primary-color);
    margin-top: 10px;
}

/* Cards */
.card-grid {
    display: grid;
    gap: 15px;
    padding-bottom: 80px; /* Space for fixed footer if any */
}

.item-card {
    background-color: var(--card-bg);
    border-radius: 10px;
    padding: 15px;
    border: 1px solid #334155;
    transition: all 0.2s;
}

.item-card.selected {
    border-color: var(--primary-color);
    background-color: #2a384b;
    box-shadow: 0 0 10px rgba(255, 215, 0, 0.2);
}

.item-title {
    font-weight: bold;
    color: var(--primary-color);
    margin-bottom: 5px;
}

.item-desc {
    font-size: 12px;
    color: #94a3b8;
}

/* Header/Stats Bar */
.stats-bar {
    background-color: rgba(15, 23, 42, 0.9);
    padding: 10px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(5px);
    border-bottom: 1px solid #334155;
}

.coin-display {
    color: var(--primary-color);
    font-weight: bold;
    display: flex;
    align-items: center;
    gap: 5px;
}

/* Auction Room */
.auction-stage {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    margin-bottom: 20px;
}

.current-item-card {
    background-color: var(--card-bg);
    padding: 20px;
    border-radius: 15px;
    border: 2px solid var(--accent-color);
    margin-bottom: 20px;
    width: 100%;
}

.current-bid {
    font-size: 32px;
    color: var(--primary-color);
    margin: 20px 0;
}

.bid-controls {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px;
    width: 100%;
}

.log-area {
    height: 150px;
    background-color: rgba(0,0,0,0.3);
    border-radius: 8px;
    padding: 10px;
    overflow-y: auto;
    font-size: 12px;
    text-align: left;
    margin-top: 20px;
    width: 100%;
}

.log-entry {
    margin-bottom: 5px;
    padding-bottom: 5px;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}

.log-entry.high-bid {
    color: var(--primary-color);
}

.log-entry.sold {
    color: var(--accent-color);
    font-weight: bold;
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.8);
    justify-content: center;
    align-items: center;
    z-index: 1000;
}

.modal.active {
    display: flex;
}

.modal-content {
    background-color: var(--card-bg);
    padding: 30px;
    border-radius: 15px;
    width: 80%;
    max-width: 300px;
    text-align: center;
}

.hidden {
    display: none;
}