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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    background: #f0f2f5;
    color: #1a1a2e;
    line-height: 1.6;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px 16px;
}

/* 头部 */
header {
    text-align: center;
    padding: 30px 0 20px;
}
header h1 {
    font-size: 1.8rem;
    color: #232f3e;
}
header p {
    color: #666;
    margin-top: 6px;
}

/* 卡片通用 */
.card {
    background: #fff;
    border-radius: 12px;
    padding: 24px;
    margin-bottom: 20px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.06);
}
.card h2 {
    font-size: 1.25rem;
    margin-bottom: 16px;
    padding-bottom: 10px;
    border-bottom: 2px solid #ff9900;
    color: #232f3e;
}

/* 步骤卡片 */
.step-cards {
    display: flex;
    flex-direction: column;
    gap: 16px;
}
.step-card {
    display: flex;
    gap: 16px;
    padding: 16px;
    background: #fafbfc;
    border-radius: 10px;
    border-left: 3px solid #ff9900;
}
.step-number {
    flex-shrink: 0;
    width: 32px; height: 32px;
    background: #ff9900;
    color: #fff;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.9rem;
    margin-top: 2px;
}
.step-content {
    flex: 1;
    min-width: 0;
}
.step-img {
    margin-top: 10px;
    max-width: 100%;
    border-radius: 8px;
    border: 1px solid #e0e0e0;
    box-shadow: 0 1px 4px rgba(0,0,0,0.08);
    cursor: pointer;
    transition: transform 0.2s;
}
.step-img:hover {
    transform: scale(1.02);
}

.steps li .step-title {
    font-weight: 600;
    color: #232f3e;
}
.steps li .step-desc {
    color: #555;
    font-size: 0.9rem;
    margin-top: 2px;
}

/* MFA 工具区 */
.mfa-tool { text-align: center; }

.input-group {
    display: flex;
    gap: 8px;
    margin-bottom: 12px;
    max-width: 500px;
    margin-left: auto;
    margin-right: auto;
}
.input-group input {
    flex: 1;
    padding: 12px 14px;
    border: 2px solid #ddd;
    border-radius: 8px;
    font-size: 1rem;
    font-family: monospace;
    transition: border-color 0.2s;
}
.input-group input:focus {
    outline: none;
    border-color: #ff9900;
}
.input-group .toggle-btn {
    padding: 8px 12px;
    background: #eee;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 0.9rem;
    white-space: nowrap;
}

.btn-generate {
    padding: 12px 32px;
    background: #ff9900;
    color: #fff;
    border: none;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s;
}
.btn-generate:hover { background: #ec7211; }

.error-msg {
    color: #d32f2f;
    font-size: 0.9rem;
    margin-top: 8px;
    min-height: 1.2em;
}

/* 结果区 */
.result-section {
    margin-top: 20px;
    padding: 20px;
    background: #f0f7ff;
    border-radius: 10px;
}
.result-section.hidden { display: none; }

.otp-display {
    font-size: 2.8rem;
    font-weight: 700;
    font-family: "Courier New", monospace;
    letter-spacing: 6px;
    color: #232f3e;
    margin: 10px 0;
}

/* 倒计时进度条 */
.timer-bar {
    max-width: 300px;
    margin: 12px auto;
    height: 6px;
    background: #ddd;
    border-radius: 3px;
    overflow: hidden;
}
.timer-bar .progress {
    height: 100%;
    background: #ff9900;
    transition: width 1s linear;
    border-radius: 3px;
}
.timer-text {
    font-size: 0.9rem;
    color: #666;
}

.btn-copy {
    margin-top: 12px;
    padding: 10px 24px;
    background: #232f3e;
    color: #fff;
    border: none;
    border-radius: 8px;
    font-size: 0.95rem;
    cursor: pointer;
    transition: background 0.2s;
}
.btn-copy:hover { background: #37475a; }

/* 安全提示 */
.security-note {
    text-align: center;
    padding: 12px;
    background: #e8f5e9;
    border-radius: 8px;
    font-size: 0.85rem;
    color: #2e7d32;
    margin-top: 8px;
}

/* 页脚 */
footer {
    text-align: center;
    padding: 20px;
    color: #999;
    font-size: 0.8rem;
}

/* 响应式 */
@media (max-width: 600px) {
    header h1 { font-size: 1.4rem; }
    .otp-display { font-size: 2rem; letter-spacing: 4px; }
    .input-group { flex-direction: column; }
    .card { padding: 16px; }
}