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

:root {
    --primary: #e74c3c;
    --primary-light: #ff6b5b;
    --primary-dark: #c0392b;
    --text: #1a1a2e;
    --text-secondary: #4a4a5a;
    --bg: #ffffff;
    --bg-secondary: #f8f9fa;
    --border: #e9ecef;
    --shadow: rgba(231, 76, 60, 0.15);
    --shadow-strong: rgba(0, 0, 0, 0.1);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
}

/* Background decoration */
.background-decoration {
    position: fixed;
    inset: 0;
    pointer-events: none;
    overflow: hidden;
    z-index: -1;
}

.circle {
    position: absolute;
    border-radius: 50%;
    background: var(--primary);
    opacity: 0.03;
}

.circle-1 {
    width: 600px;
    height: 600px;
    top: -200px;
    right: -100px;
}

.circle-2 {
    width: 400px;
    height: 400px;
    bottom: -100px;
    left: -100px;
}

.circle-3 {
    width: 300px;
    height: 300px;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
}

/* Container */
.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 40px 24px 60px;
}

/* Header */
.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 48px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
}

/* Navigation */
.nav {
    display: flex;
    gap: 8px;
}

.nav-link {
    padding: 8px 16px;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 500;
    color: var(--text-secondary);
    text-decoration: none;
    transition: all 0.2s ease;
}

.nav-link:hover {
    color: var(--text);
    background: var(--bg-secondary);
}

.nav-link.active {
    color: var(--primary);
    background: rgba(231, 76, 60, 0.1);
}

.nav-link-accent {
    color: var(--primary) !important;
}

.logo-icon {
    width: 48px;
    height: 48px;
    border-radius: 4px;
    box-shadow: 0 4px 12px var(--shadow);
}

.logo-text {
    font-size: 24px;
    font-weight: 700;
    color: var(--text);
}

/* Hero */
.hero {
    text-align: center;
    margin-bottom: 20px;
}

.success-badge {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: linear-gradient(135deg, #10b981 0%, #059669 100%);
    color: white;
    padding: 8px 20px;
    border-radius: 50px;
    font-size: 14px;
    font-weight: 600;
    margin-bottom: 24px;
    box-shadow: 0 4px 12px rgba(16, 185, 129, 0.3);
}

.checkmark {
    width: 18px;
    height: 18px;
}

.title {
    font-size: clamp(32px, 5vw, 48px);
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 16px;
    color: var(--text);
}

.highlight {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-light) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    font-size: 18px;
    color: var(--text-secondary);
    max-width: 500px;
    margin: 0 auto;
}

/* Steps */
.steps {
    display: flex;
    flex-direction: column;
    gap: 24px;
    margin-bottom: 48px;
}

.step {
    display: flex;
    flex-direction: column;
    gap: 4px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 20px;
    padding: 24px;
    box-shadow: 0 4px 20px var(--shadow-strong);
}


.step-content h2 {
    font-size: 20px;
    font-weight: 600;
    margin-bottom: 4px;
    color: var(--text);
}

.step-content p {
    font-size: 15px;
    color: var(--text-secondary);
    line-height: 1.6;
}

.step-content strong {
    color: var(--primary);
    font-weight: 600;
}

.step-image {
    margin-top: 0;
}

.step-image img {
    width: 100%;
    border-radius: 12px;
    box-shadow: 0 4px 20px var(--shadow-strong);
    border: 1px solid var(--border);
}

/* Features / Shortcuts */
.features {
    background: var(--bg-secondary);
    border-radius: 20px;
    padding: 40px;
    margin-bottom: 48px;
}

.features-title {
    text-align: center;
    font-size: 24px;
    font-weight: 600;
    margin-bottom: 32px;
    color: var(--text);
}

.shortcuts-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 16px;
}

.shortcut {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    padding: 20px;
    background: var(--bg);
    border-radius: 12px;
    border: 1px solid var(--border);
}

.shortcut kbd {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 40px;
    height: 36px;
    padding: 0 12px;
    background: linear-gradient(180deg, #fff 0%, #f0f0f0 100%);
    border: 1px solid #d0d0d0;
    border-radius: 8px;
    font-family: inherit;
    font-size: 14px;
    font-weight: 600;
    color: var(--text);
    box-shadow: 0 2px 0 #c0c0c0;
}

.shortcut span {
    font-size: 13px;
    color: var(--text-secondary);
    text-align: center;
}

/* CTA */
.cta {
    text-align: center;
    padding: 32px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    border-radius: 20px;
    margin-top: 48px;
    margin-bottom: 48px;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 32px;
    border-radius: 12px;
    font-size: 16px;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.2s ease;
    cursor: pointer;
}

.btn-primary {
    background: white;
    color: var(--primary);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.2);
}

.btn-secondary {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: var(--bg);
    color: var(--primary);
    border: 2px solid var(--primary);
    box-shadow: 0 2px 8px var(--shadow);
}

.btn-secondary:hover {
    background: var(--primary);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px var(--shadow);
}

.btn-secondary svg {
    transition: transform 0.2s ease;
}

.btn-secondary:hover svg:last-child {
    transform: translateX(4px);
}

.btn-secondary:hover svg:first-child {
    transform: translateX(-4px);
}

/* Navigation Actions */
.nav-actions {
    display: flex;
    justify-content: center;
    gap: 12px;
    margin-top: 48px;
}

/* Guide Page */
.guide-content {
    margin-bottom: 48px;
}

/* Section Title */
.section-title {
    font-size: 24px;
    font-weight: 600;
    text-align: center;
    margin-bottom: 24px;
    color: var(--text);
}

/* Controls Section */
.controls-section {
    margin-bottom: 48px;
}

.controls-showcase {
    display: flex;
    justify-content: center;
    gap: 12px;
    overflow-x: auto;
    padding-bottom: 8px;
}

.control-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 6px;
    padding: 12px 14px;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 12px;
    box-shadow: 0 2px 8px var(--shadow-strong);
    flex-shrink: 0;
}

.control-item-wide {
    padding: 12px 16px;
}

.control-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: var(--bg-secondary);
    border-radius: 10px;
    color: var(--primary);
}

.control-icon svg {
    stroke: var(--primary);
}

.control-item span {
    font-size: 13px;
    color: var(--text-secondary);
    font-weight: 500;
}

.control-slider {
    display: flex;
    align-items: center;
    gap: 8px;
}

.slider-track {
    width: 80px;
    height: 6px;
    background: linear-gradient(90deg, var(--border) 0%, var(--primary) 100%);
    border-radius: 3px;
}

.slider-label {
    font-size: 11px;
    color: var(--text-secondary);
    font-weight: 500;
}

/* Tip Section */
.tip-section {
    margin-bottom: 48px;
}

.tip-card {
    display: flex;
    align-items: flex-start;
    gap: 20px;
    padding: 24px;
    background: linear-gradient(135deg, rgba(231, 76, 60, 0.05) 0%, rgba(231, 76, 60, 0.1) 100%);
    border: 1px solid rgba(231, 76, 60, 0.2);
    border-radius: 16px;
}

.tip-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 56px;
    height: 56px;
    background: var(--bg);
    border-radius: 12px;
    flex-shrink: 0;
    box-shadow: 0 2px 8px var(--shadow);
}

.tip-icon svg {
    stroke: var(--primary);
}

.tip-content h3 {
    font-size: 18px;
    font-weight: 600;
    color: var(--text);
    margin-bottom: 8px;
}

.tip-content p {
    font-size: 15px;
    color: var(--text-secondary);
    line-height: 1.6;
}

.tip-content strong {
    color: var(--primary);
}

/* Features Section */
.features-section {
    margin-bottom: 48px;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
}

.feature-card {
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 24px;
    text-align: center;
    box-shadow: 0 2px 8px var(--shadow-strong);
    transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.feature-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 16px var(--shadow-strong);
}

.feature-icon {
    font-size: 32px;
    margin-bottom: 12px;
}

.feature-card h3 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text);
}

.feature-card p {
    font-size: 14px;
    color: var(--text-secondary);
    line-height: 1.5;
}

/* Hotkeys Section */
.hotkeys-section {
    background: var(--bg-secondary);
    border-radius: 20px;
    padding: 32px;
    margin-bottom: 48px;
}

.hotkeys-grid-guide {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 12px;
}

.hotkey-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    background: var(--bg);
    border-radius: 10px;
    border: 1px solid var(--border);
}

.hotkey-item .hotkey-key {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 48px;
    height: 32px;
    padding: 0 10px;
    background: linear-gradient(180deg, #fff 0%, #f0f0f0 100%);
    border: 1px solid #d0d0d0;
    border-radius: 6px;
    font-size: 13px;
    font-weight: 600;
    color: var(--text);
    box-shadow: 0 2px 0 #c0c0c0;
}

.hotkey-item .hotkey-desc {
    font-size: 14px;
    color: var(--text-secondary);
}

@media (max-width: 640px) {
    .features-grid {
        grid-template-columns: 1fr;
    }

    .hotkeys-grid-guide {
        grid-template-columns: 1fr;
    }

    .hotkeys-section {
        padding: 24px;
    }

    .controls-showcase {
        justify-content: flex-start;
        gap: 10px;
    }

    .control-item {
        padding: 10px 12px;
    }

    .tip-card {
        flex-direction: column;
        text-align: center;
        align-items: center;
    }
}

.guide-placeholder {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 64px 32px;
    background: var(--bg-secondary);
    border: 2px dashed var(--border);
    border-radius: 20px;
    text-align: center;
}

.guide-placeholder svg {
    color: var(--text-secondary);
    margin-bottom: 24px;
    opacity: 0.5;
}

.guide-placeholder h2 {
    font-size: 24px;
    font-weight: 600;
    color: var(--text);
    margin-bottom: 8px;
}

.guide-placeholder p {
    font-size: 16px;
    color: var(--text-secondary);
}

/* Footer */
.footer {
    text-align: center;
    padding-top: 32px;
    border-top: 1px solid var(--border);
}

.footer p {
    color: var(--text-secondary);
    margin-bottom: 16px;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 24px;
}

.footer-links a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s ease;
}

.footer-links a:hover {
    color: var(--primary-dark);
    text-decoration: underline;
}

.other-extensions {
    margin-top: 40px;
    text-align: center;
}

.other-extensions-label {
    font-size: 14px;
    font-weight: 600;
    letter-spacing: 0.08em;
    text-transform: uppercase;
    color: var(--text-secondary);
    margin-bottom: 16px;
}

.other-extension-card {
    display: block;
    text-decoration: none;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 18px;
    padding: 20px 24px;
    box-shadow: 0 4px 20px var(--shadow);
    transition: transform 0.2s ease, box-shadow 0.2s ease, border-color 0.2s ease;
}

.other-extension-card:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 24px var(--shadow-strong);
    border-color: #d8c690;
}

.other-extension-name {
    display: block;
    font-size: 22px;
    font-weight: 600;
    color: var(--text);
    margin-bottom: 8px;
}

.other-extension-copy {
    display: block;
    font-size: 15px;
    color: var(--text-secondary);
}

.other-extensions-grid {
    display: grid;
    gap: 14px;
}

/* Responsive */
@media (max-width: 640px) {
    .header {
        flex-direction: column;
        gap: 16px;
    }

    .nav {
        width: 100%;
        justify-content: center;
    }

    .container {
        padding: 24px 16px 40px;
    }

    .step {
        padding: 24px;
    }

    .features {
        padding: 24px;
    }

    .shortcuts-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .cta {
        padding: 32px 20px;
    }
}