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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    background: #f5f5f5;
    color: #1a1a1a;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
}

.container {
    text-align: center;
    padding: 2.5rem;
    max-width: 500px;
    width: 90%;
}

h1 {
    font-size: 2rem;
    font-weight: 700;
    color: #ff6900;
    margin-bottom: 0.3rem;
}

.logo {
    width: 120px;
    margin-bottom: 1rem;
}

.subtitle {
    color: #666;
    font-size: 0.95rem;
    margin-bottom: 0.2rem;
}

.subtitle-note {
    color: #999;
    font-size: 0.85rem;
    margin-bottom: 1.5rem;
}

.code-box {
    background: #fff;
    border: 2px solid #ff6900;
    border-radius: 12px;
    padding: 1.5rem 1rem;
    margin-bottom: 1.5rem;
    min-height: 70px;
    display: flex;
    align-items: center;
    justify-content: center;
}

#code-text {
    font-size: 1.8rem;
    font-weight: 700;
    letter-spacing: 0.15em;
    font-family: "SF Mono", "Fira Code", "Consolas", monospace;
    color: #1a1a1a;
    word-break: break-all;
}

#code-text.no-code {
    font-size: 0.95rem;
    font-weight: 400;
    letter-spacing: normal;
    font-family: inherit;
    color: #888;
}

.buttons {
    display: flex;
    gap: 0.6rem;
    justify-content: center;
    flex-wrap: wrap;
}

button {
    padding: 0.7rem 1.2rem;
    border: none;
    border-radius: 8px;
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s, opacity 0.2s;
}

#btn-copy {
    background: #ff6900;
    color: #fff;
}

#btn-copy:hover:not(:disabled) {
    background: #e55d00;
}

#btn-used {
    background: #e8e8e8;
    color: #333;
}

#btn-used:hover:not(:disabled) {
    background: #d5d5d5;
}

#btn-next {
    background: #e8e8e8;
    color: #333;
}

#btn-next:hover:not(:disabled) {
    background: #d5d5d5;
}

button:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.info {
    margin-top: 1rem;
    font-size: 0.85rem;
    color: #ff6900;
    min-height: 1.2em;
}