:root {
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --teal: #0d9488;
    --teal-hover: #0f766e;
    --amazon-orange: #ff9900;
    --amazon-bg: #fffbf4;
    --slate-50: #f8fafc;
    --slate-100: #f1f5f9;
    --slate-200: #e2e8f0;
    --slate-300: #cbd5e1;
    --slate-400: #94a3b8;
    --slate-500: #64748b;
    --slate-600: #475569;
    --slate-700: #334155;
    --slate-800: #1e293b;
    --slate-900: #0f172a;
}

body {
    margin: 0;
    font-family: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: var(--slate-50);
    color: var(--slate-700);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header 導覽列 */
.navbar {
    background-color: #ffffff;
    border-bottom: 1px solid var(--slate-200);
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: 0 1px 3px rgba(0, 0, 0, 0.02);
}
.nav-logo { font-size: 1.35rem; font-weight: 800; color: var(--primary); display: flex; align-items: center; gap: 0.5rem; letter-spacing: -0.02em; }
.nav-links { display: flex; gap: 1.5rem; font-size: 0.9rem; font-weight: 500; }
.nav-link { color: var(--slate-500); text-decoration: none; transition: color 0.2s; }
.nav-link:hover, .nav-link.active { color: var(--primary); font-weight: 600; }

/* 主要版面佈局 */
.main-container { flex-grow: 1; max-width: 68rem; width: 100%; margin: 0 auto; padding: 4rem 1.5rem; box-sizing: border-box; }
.hero-section { text-align: center; margin-bottom: 3.5rem; }
.badge { background-color: #eff6ff; color: #1d4ed8; font-size: 0.75rem; font-weight: 700; padding: 0.35rem 0.85rem; border-radius: 9999px; text-transform: uppercase; letter-spacing: 0.05em; border: 1px solid #dbeafe; }
.hero-title { font-size: 2.5rem; font-weight: 850; color: var(--slate-900); margin-top: 1rem; margin-bottom: 1rem; letter-spacing: -0.03em; line-height: 1.15; }
@media (min-width: 768px) { .hero-title { font-size: 3.5rem; } }
.hero-subtitle { font-size: 1.15rem; color: var(--slate-500); max-w: 44rem; margin: 0 auto; line-height: 1.6; }

/* Tool Grid 工作區 */
.tool-grid { background-color: #ffffff; border-radius: 1.25rem; box-shadow: 0 20px 25px -5px rgba(0,0,0,0.05); border: 1px solid var(--slate-200); padding: 2.5rem; display: grid; gap: 3rem; }
@media (min-width: 768px) { .tool-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); } }

/* 左側表單控制項 */
.form-panel { display: flex; flex-direction: column; justify-content: center; }
.form-label { display: block; font-size: 0.9rem; font-weight: 700; color: var(--slate-800); margin-bottom: 0.5rem; }
.input-field { width: 100%; padding: 0.85rem 1.15rem; border-radius: 0.6rem; border: 1px solid var(--slate-300); font-size: 0.95rem; outline: none; transition: all 0.2s; box-sizing: border-box; margin-bottom: 1.25rem; }
.input-field:focus { border-color: var(--primary); box-shadow: 0 0 0 4px rgba(37, 99, 235, 0.15); }
.helper-text { font-size: 0.8rem; color: var(--slate-500); margin-top: -0.5rem; margin-bottom: 1.5rem; line-height: 1.4; }
.text-link { color: var(--primary); text-decoration: underline; font-weight: 600; }

/* 按鈕類別（美式流暢漸變效果） */
.btn-primary, .btn-secondary, .btn-teal { width: 100%; font-weight: 700; padding: 0.9rem 1.5rem; border-radius: 0.6rem; transition: all 0.2s; border: none; cursor: pointer; text-align: center; text-decoration: none; box-sizing: border-box; display: block; font-size: 0.95rem; }
.btn-primary { background-color: var(--primary); color: #ffffff; box-shadow: 0 4px 6px -1px rgba(37, 99, 235, 0.2); }
.btn-primary:hover { background-color: var(--primary-hover); transform: translateY(-1px); }
.btn-secondary { background-color: var(--slate-800); color: #ffffff; }
.btn-secondary:hover { background-color: var(--slate-900); transform: translateY(-1px); }
.btn-teal { background-color: var(--teal); color: #ffffff; box-shadow: 0 4px 6px -1px rgba(13, 148, 136, 0.2); }
.btn-teal:hover { background-color: var(--teal-hover); transform: translateY(-1px); }

.features-list { margin-top: 2rem; border-top: 1px solid var(--slate-100); padding-top: 1.25rem; font-size: 0.8rem; color: var(--slate-500); line-height: 1.6; }
.features-list p { margin: 0.75rem 0; }

/* 右側預覽面板 */
.preview-panel { background-color: var(--slate-100); border-radius: 1rem; border: 2px dashed var(--slate-300); padding: 2rem; display: flex; flex-direction: column; align-items: center; justify-content: center; min-height: 400px; box-sizing: border-box; }
.placeholder-content { color: var(--slate-400); text-align: center; }
.placeholder-icon { font-size: 3.5rem; display: block; margin-bottom: 1rem; animation: bounce 2s infinite; }
.placeholder-text { font-size: 0.9rem; line-height: 1.5; font-weight: 500; }

/* 解鎖後的 Kit 內容與亞馬遜卡片設計 */
.kit-content { width: 100%; text-align: center; }
.kit-title { font-size: 1.25rem; font-weight: 800; color: var(--slate-900); margin-bottom: 1.25rem; }
.qr-wrapper { background-color: #ffffff; padding: 1.25rem; border-radius: 0.75rem; box-shadow: 0 10px 15px -3px rgba(0,0,0,0.05); display: inline-block; margin-bottom: 1.75rem; border: 1px solid var(--slate-200); }
.qr-wrapper img { width: 13rem; height: 13rem; display: block; }
.action-buttons { display: flex; flex-direction: column; gap: 0.65rem; max-width: 22rem; margin: 0 auto 2rem auto; }

/* 亞馬遜電商卡片區塊 */
.affiliate-box { border-top: 1px solid var(--slate-200); padding-top: 1.5rem; text-align: left; width: 100%; }
.affiliate-label { font-size: 0.8rem; font-weight: 700; color: var(--slate-500); text-transform: uppercase; letter-spacing: 0.02em; margin-bottom: 0.75rem; margin-top: 0; }
.amazon-card { display: block; background-color: var(--amazon-bg); border: 1px solid #feebc8; border-radius: 0.75rem; padding: 1.25rem; text-decoration: none; transition: all 0.2s ease-in-out; }
.amazon-card:hover { border-color: var(--amazon-orange); transform: scale(1.01); box-shadow: 0 4px 12px rgba(255, 153, 0, 0.08); }
.amazon-card-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 0.5rem; }
.amazon-badge { font-size: 0.7rem; font-weight: 800; color: #dd6b20; background-color: #feebc8; padding: 0.15rem 0.5rem; border-radius: 4px; text-transform: uppercase; }
.amazon-tag { font-size: 0.75rem; font-weight: 900; color: #00a8e8; font-style: italic; }
.amazon-product-title { font-size: 0.9rem; font-weight: 700; color: var(--slate-900); margin: 0 0 0.35rem 0; line-height: 1.4; }
.amazon-product-desc { font-size: 0.8rem; color: var(--slate-500); margin: 0 0 1rem 0; line-height: 1.5; }
.amazon-cta { font-size: 0.85rem; font-weight: 700; color: #c05621; display: inline-block; }
.amazon-card:hover .amazon-cta { color: var(--amazon-orange); }

.hidden { display: none !important; }
.ftc-disclosure { font-size: 0.7rem; color: var(--slate-400); text-align: center; line-height: 1.5; max-w: 48rem; margin: 3rem auto 0 auto; }
.footer { background-color: #ffffff; border-top: 1px solid var(--slate-200); padding: 2rem 0; text-align: center; font-size: 0.8rem; color: var(--slate-400); margin-top: auto; }
.footer a { color: var(--slate-400); text-decoration: underline; margin-left: 0.75rem; }

@keyframes bounce { 0%, 100% { transform: translateY(0); } 50% { transform: translateY(-6px); } }