/* Reset and Base Styles */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary: #64748b;
    --accent: #0ea5e9;
    --text: #1e293b;
    --text-light: #475569;
    --bg: #ffffff;
    --bg-alt: #f8fafc;
    --border: #e2e8f0;
    --success: #22c55e;
    --shadow: 0 1px 3px rgba(0,0,0,0.1);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.1);
    --radius: 8px;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    line-height: 1.6;
    color: var(--text);
    background: var(--bg);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
.header {
    background: linear-gradient(135deg, var(--primary) 0%, var(--accent) 100%);
    color: white;
    padding: 60px 0;
    text-align: center;
}

.header h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 10px;
}

.tagline {
    font-size: 1.2rem;
    opacity: 0.9;
}

/* Navigation */
.nav {
    background: var(--bg);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 100;
    box-shadow: var(--shadow);
}

.nav-links {
    display: flex;
    list-style: none;
    justify-content: center;
    gap: 10px;
    padding: 15px 0;
    flex-wrap: wrap;
}

.nav-links a {
    color: var(--text);
    text-decoration: none;
    padding: 8px 16px;
    border-radius: var(--radius);
    transition: all 0.2s;
    font-weight: 500;
}

.nav-links a:hover {
    background: var(--bg-alt);
    color: var(--primary);
}

/* Sections */
.section {
    padding: 60px 0;
    border-bottom: 1px solid var(--border);
}

.section:last-child {
    border-bottom: none;
}

.section h2 {
    font-size: 2rem;
    margin-bottom: 20px;
    color: var(--text);
}

.section h3 {
    font-size: 1.4rem;
    margin: 25px 0 15px;
    color: var(--text);
}

.intro {
    padding: 40px 0;
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.intro h2 {
    font-size: 2.2rem;
    margin-bottom: 15px;
}

.intro p {
    font-size: 1.1rem;
    color: var(--text-light);
}

/* Technique Cards */
.technique-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 25px;
    margin-top: 30px;
}

.technique-card {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 25px;
    box-shadow: var(--shadow);
}

.technique-card h3 {
    color: var(--primary);
    margin-top: 0;
    margin-bottom: 15px;
    font-size: 1.3rem;
}

.technique-card .steps {
    background: var(--bg-alt);
    padding: 15px;
    border-radius: var(--radius);
    margin: 15px 0;
}

.technique-card .steps h4 {
    font-size: 0.95rem;
    margin-bottom: 10px;
    color: var(--secondary);
}

.technique-card ol, .technique-card ul {
    margin-left: 20px;
}

.technique-card li {
    margin-bottom: 8px;
    color: var(--text-light);
}

.tip {
    font-size: 0.9rem;
    color: var(--text-light);
    padding: 10px;
    background: #fef3c7;
    border-radius: var(--radius);
    border-left: 3px solid #f59e0b;
}

/* Organization Section */
.org-content {
    max-width: 900px;
}

.org-content > p {
    margin-bottom: 15px;
    color: var(--text-light);
}

.org-content a {
    color: var(--primary);
    text-decoration: none;
}

.org-content a:hover {
    text-decoration: underline;
}

.cube-system {
    background: var(--bg-alt);
    padding: 25px;
    border-radius: var(--radius);
    margin: 20px 0;
}

.cube-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
    margin-top: 15px;
}

.cube-item {
    background: var(--bg);
    padding: 15px;
    border-radius: var(--radius);
    text-align: center;
    border: 1px solid var(--border);
}

.cube-size {
    display: inline-block;
    padding: 5px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    margin-bottom: 10px;
}

.cube-size.large { background: #dbeafe; color: #1e40af; }
.cube-size.medium { background: #dcfce7; color: #166534; }
.cube-size.small { background: #fef3c7; color: #92400e; }
.cube-size.slim { background: #f3e8ff; color: #7e22ce; }

.cube-item p {
    font-size: 0.9rem;
    color: var(--text-light);
    margin: 0;
}

.zone-list {
    list-style: none;
    margin: 15px 0;
}

.zone-list li {
    padding: 10px 0;
    border-bottom: 1px solid var(--border);
    color: var(--text-light);
}

.zone-list li:last-child {
    border-bottom: none;
}

.cable-tips {
    background: var(--bg-alt);
    padding: 20px;
    border-radius: var(--radius);
    margin-top: 15px;
}

.cable-tips h4 {
    margin-bottom: 10px;
}

.cable-tips ul {
    margin-left: 20px;
}

.cable-tips li {
    margin-bottom: 8px;
    color: var(--text-light);
}

/* Checklist */
.checklist-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 25px;
    margin-top: 30px;
}

.checklist-category {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 20px;
}

.checklist-category h3 {
    font-size: 1.1rem;
    margin: 0 0 15px 0;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--primary);
    color: var(--primary);
}

.checklist {
    list-style: none;
}

.checklist li {
    padding: 8px 0;
    border-bottom: 1px solid var(--border);
}

.checklist li:last-child {
    border-bottom: none;
}

.checklist label {
    display: flex;
    align-items: center;
    gap: 10px;
    cursor: pointer;
    color: var(--text-light);
}

.checklist input[type="checkbox"] {
    width: 18px;
    height: 18px;
    accent-color: var(--primary);
}

.checklist input[type="checkbox"]:checked + span,
.checklist label:has(input:checked) {
    text-decoration: line-through;
    opacity: 0.6;
}

.checklist-actions {
    display: flex;
    gap: 15px;
    justify-content: center;
    margin-top: 30px;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 24px;
    border-radius: var(--radius);
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    border: none;
    transition: all 0.2s;
    font-size: 1rem;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
}

.btn-secondary {
    background: var(--bg-alt);
    color: var(--text);
    border: 1px solid var(--border);
}

.btn-secondary:hover {
    background: var(--border);
}

.btn-affiliate {
    background: #ff9900;
    color: #111;
    display: block;
    text-align: center;
    margin-top: 15px;
}

.btn-affiliate:hover {
    background: #e68a00;
}

/* Tips Grid */
.tips-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 20px;
    margin-top: 30px;
}

.tip-card {
    background: var(--bg-alt);
    padding: 25px;
    border-radius: var(--radius);
    border-left: 4px solid var(--accent);
}

.tip-card h3 {
    margin: 0 0 10px 0;
    color: var(--text);
    font-size: 1.1rem;
}

.tip-card p {
    color: var(--text-light);
    margin: 0;
}

/* Products Section */
.products-section {
    background: var(--bg-alt);
}

.products-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 25px;
    margin-top: 30px;
}

.product-card {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 25px;
    box-shadow: var(--shadow);
}

.product-card h3 {
    margin: 0 0 10px 0;
    font-size: 1.15rem;
    color: var(--text);
}

.product-card > p {
    color: var(--text-light);
    font-size: 0.95rem;
    margin-bottom: 15px;
}

.product-features {
    list-style: none;
    margin: 15px 0;
    padding: 15px;
    background: var(--bg-alt);
    border-radius: var(--radius);
}

.product-features li {
    padding: 5px 0;
    color: var(--text-light);
    font-size: 0.9rem;
    position: relative;
    padding-left: 20px;
}

.product-features li::before {
    content: "✓";
    position: absolute;
    left: 0;
    color: var(--success);
    font-weight: bold;
}

/* Carry-On Section */
.carry-on-content {
    max-width: 800px;
}

.carry-on-content > p {
    color: var(--text-light);
    margin-bottom: 20px;
}

.capsule-example {
    background: var(--bg-alt);
    padding: 25px;
    border-radius: var(--radius);
    margin: 20px 0;
}

.capsule-example h4 {
    margin-bottom: 15px;
    color: var(--text);
}

.capsule-example ul {
    margin-left: 20px;
}

.capsule-example li {
    padding: 5px 0;
    color: var(--text-light);
}

/* Footer */
.footer {
    background: var(--text);
    color: white;
    padding: 40px 0;
    text-align: center;
}

.footer p {
    margin-bottom: 10px;
}

.affiliate-disclosure {
    font-size: 0.85rem;
    opacity: 0.7;
    max-width: 600px;
    margin: 0 auto;
}

/* Responsive */
@media (max-width: 768px) {
    .header {
        padding: 40px 0;
    }

    .header h1 {
        font-size: 2rem;
    }

    .nav-links {
        gap: 5px;
    }

    .nav-links a {
        padding: 8px 12px;
        font-size: 0.9rem;
    }

    .section {
        padding: 40px 0;
    }

    .section h2 {
        font-size: 1.6rem;
    }

    .intro h2 {
        font-size: 1.8rem;
    }

    .checklist-actions {
        flex-direction: column;
        align-items: stretch;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 15px;
    }

    .header h1 {
        font-size: 1.7rem;
    }

    .tagline {
        font-size: 1rem;
    }

    .technique-card, .product-card, .checklist-category {
        padding: 20px;
    }
}