/* CSS Custom Properties */
:root {
    --color-primary: #2563eb;
    --color-primary-hover: #1d4ed8;
    --color-text: #111827;
    --color-text-light: #6b7280;
    --color-background: #ffffff;
    --color-border: #e5e7eb;
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --max-width: 1120px;
}

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

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-family);
    color: var(--color-text);
    background-color: var(--color-background);
    line-height: 1.6;
}

/* Container */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

/* Typography */
h1, h2, h3 {
    line-height: 1.2;
    font-weight: 600;
}

h1 {
    font-size: 3rem;
    letter-spacing: -0.02em;
}

h2 {
    font-size: 2rem;
}

h3 {
    font-size: 1.25rem;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 12px 24px;
    font-size: 1rem;
    font-weight: 500;
    text-decoration: none;
    border-radius: 8px;
    transition: all 0.2s ease;
    cursor: pointer;
    border: none;
}

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

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

.btn-secondary {
    background-color: transparent;
    color: var(--color-primary);
    border: 1px solid var(--color-primary);
}

.btn-secondary:hover {
    background-color: var(--color-primary);
    color: #ffffff;
}

.btn-large {
    padding: 16px 32px;
    font-size: 1.125rem;
}

/* Header */
.header {
    padding: 20px 0;
    border-bottom: 1px solid var(--color-border);
}

.header-content {
    display: flex;
    justify-content: center;
    align-items: center;
}

.logo-group {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--color-text);
    text-decoration: none;
}

.header-tagline {
    font-size: 0.875rem;
    color: var(--color-text-light);
}

.header-link {
    color: var(--color-primary);
    text-decoration: none;
}

.header-link:hover {
    text-decoration: underline;
}

/* Hero Section */
.hero {
    padding: 100px 0;
    text-align: center;
}

.hero h1 {
    margin-bottom: 24px;
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--color-text-light);
    margin-bottom: 40px;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* Features Section */
.features {
    padding: 80px 0;
    background-color: #f9fafb;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 48px;
}

.feature {
    text-align: center;
}

.feature-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 64px;
    height: 64px;
    background-color: #eff6ff;
    color: var(--color-primary);
    border-radius: 12px;
    margin-bottom: 20px;
}

.feature h3 {
    margin-bottom: 12px;
}

.feature p {
    color: var(--color-text-light);
}

/* CTA Section */
.cta {
    padding: 80px 0;
    text-align: center;
}

.cta h2 {
    margin-bottom: 32px;
}

/* Footer */
.footer {
    padding: 40px 0;
    border-top: 1px solid var(--color-border);
    text-align: center;
}

.footer p {
    color: var(--color-text-light);
    font-size: 0.875rem;
}

.footer-link {
    color: var(--color-primary);
    text-decoration: none;
}

.footer-link:hover {
    text-decoration: underline;
}

/* Upload Area */
.upload-area {
    max-width: 500px;
    margin: 0 auto 32px;
}

.dropzone {
    border: 2px dashed var(--color-border);
    border-radius: 12px;
    padding: 48px 24px;
    cursor: pointer;
    transition: all 0.2s ease;
    color: var(--color-text-light);
}

.dropzone:hover {
    border-color: var(--color-primary);
    background-color: #f8fafc;
}

.dropzone.dragover {
    border-color: var(--color-primary);
    background-color: #eff6ff;
}

.dropzone svg {
    margin-bottom: 16px;
    color: var(--color-primary);
}

.dropzone-text {
    font-size: 1.125rem;
    font-weight: 500;
    color: var(--color-text);
    margin-bottom: 8px;
}

.dropzone-hint {
    font-size: 0.875rem;
}

/* Progress Area */
.progress-area {
    max-width: 500px;
    margin: 0 auto 32px;
}

.progress-container {
    height: 8px;
    background-color: #e5e7eb;
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 12px;
}

.progress-bar {
    height: 100%;
    background-color: var(--color-primary);
    width: 0%;
    transition: width 0.3s ease;
}

.progress-text {
    font-size: 0.875rem;
    color: var(--color-text-light);
}

/* Result Area */
.result-area {
    max-width: 500px;
    margin: 0 auto 32px;
}

.result-warning {
    font-size: 1.25rem;
    font-weight: 600;
    color: #dc2626;
    margin-bottom: 16px;
}

.result-label {
    font-size: 0.875rem;
    color: var(--color-text-light);
    margin-bottom: 12px;
}

.result-link-container {
    display: flex;
    gap: 12px;
    align-items: center;
    background-color: #f9fafb;
    border: 1px solid var(--color-border);
    border-radius: 8px;
    padding: 12px 16px;
    margin-bottom: 16px;
}

.result-link {
    flex: 1;
    color: var(--color-primary);
    text-decoration: none;
    word-break: break-all;
    font-family: monospace;
}

.result-link:hover {
    text-decoration: underline;
}

.result-area .btn-secondary {
    padding: 8px 16px;
    font-size: 0.875rem;
}

.result-area .btn-secondary.copied {
    background-color: #10b981;
    border-color: #10b981;
    color: #ffffff;
}

.btn-text {
    background: none;
    border: none;
    color: var(--color-text-light);
    font-size: 0.875rem;
    cursor: pointer;
    text-decoration: underline;
}

.btn-text:hover {
    color: var(--color-text);
}

/* Error Area */
.error-area {
    max-width: 500px;
    margin: 0 auto 32px;
    padding: 24px;
    background-color: #fef2f2;
    border: 1px solid #fecaca;
    border-radius: 8px;
}

.error-text {
    color: #dc2626;
    margin-bottom: 12px;
}

/* CTA Link */
.cta-link {
    display: block;
    margin-top: 24px;
    margin-bottom: 16px;
}

/* Utility */
.hidden {
    display: none !important;
}

/* Responsive Design */
@media (max-width: 768px) {
    h1 {
        font-size: 2.25rem;
    }

    h2 {
        font-size: 1.75rem;
    }

    .hero {
        padding: 60px 0;
    }

    .hero-subtitle {
        font-size: 1.125rem;
    }

    .features {
        padding: 60px 0;
    }

    .features-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .cta {
        padding: 60px 0;
    }
}

@media (max-width: 480px) {
    h1 {
        font-size: 1.875rem;
    }

    .container {
        padding: 0 16px;
    }

    .btn-large {
        padding: 14px 28px;
        font-size: 1rem;
    }
}