/* ==========================================
   1. Reset & General Styles
   ========================================== */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, Ubuntu, Cantarell, "Open Sans", "Helvetica Neue", sans-serif;
    background-color: #f8fafc;
    color: #1e293b;
    line-height: 1.6;
}

/* ==========================================
   2. Header & Navigation
   ========================================== */
.site-header {
    background-color: #ffffff;
    border-bottom: 1px solid #e2e8f0;
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 1rem 1.5rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo-link {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    text-decoration: none;
    color: #0f172a;
    font-weight: 700;
    font-size: 1.25rem;
}

.logo-icon {
    font-size: 1.5rem;
}

.nav-list {
    display: flex;
    list-style: none;
    gap: 1.5rem;
}

.nav-link {
    text-decoration: none;
    color: #64748b;
    font-weight: 500;
    font-size: 0.95rem;
    transition: color 0.2s ease;
}

.nav-link:hover,
.nav-link.active {
    color: #2563eb;
    font-weight: 600;
}

/* ==========================================
   3. Main Content & Layout
   ========================================== */
.main-container {
    max-width: 1000px;
    margin: 2.5rem auto;
    padding: 0 1.5rem;
}

.content-header h1 {
    font-size: 2rem;
    color: #0f172a;
    margin-bottom: 0.5rem;
}

.meta-info {
    color: #64748b;
    font-size: 1rem;
}

/* ==========================================
   4. Tool Interface Box
   ========================================== */
.tool-box {
    background: #ffffff;
    border: 1px solid #e2e8f0;
    border-radius: 12px;
    padding: 2rem;
    box-shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.05);
    margin-top: 1.5rem;
}

.upload-area {
    border: 2px dashed #cbd5e1;
    border-radius: 8px;
    padding: 2rem;
    text-align: center;
    background-color: #f8fafc;
    transition: border-color 0.2s ease, background-color 0.2s ease;
}

.upload-area:hover {
    border-color: #2563eb;
    background-color: #eff6ff;
}

/* Form Controls & Textareas */
textarea {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid #cbd5e1;
    border-radius: 6px;
    font-family: inherit;
    font-size: 0.95rem;
    outline: none;
    transition: border-color 0.2s ease;
    resize: vertical;
}

textarea:focus {
    border-color: #2563eb;
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

/* Buttons Styling */
button {
    font-family: inherit;
    font-size: 0.95rem;
    transition: transform 0.1s ease, opacity 0.2s ease;
}

button:hover {
    opacity: 0.9;
}

button:active {
    transform: scale(0.98);
}

/* ==========================================
   5. SEO & Guide Section
   ========================================== */
.guide-section {
    margin-top: 3rem;
    background: #ffffff;
    border-radius: 8px;
    padding: 2rem;
    border: 1px solid #e2e8f0;
}

.guide-section h2 {
    font-size: 1.5rem;
    color: #0f172a;
    margin-bottom: 1rem;
}

.guide-section h3 {
    font-size: 1.2rem;
    color: #1e293b;
    margin-top: 1.5rem;
    margin-bottom: 0.75rem;
}

.guide-steps {
    padding-left: 1.25rem;
}

.guide-steps li {
    margin-bottom: 0.5rem;
}

/* ==========================================
   6. Footer
   ========================================== */
.site-footer {
    background-color: #ffffff;
    border-top: 1px solid #e2e8f0;
    margin-top: 4rem;
    padding: 1.5rem 0;
    text-align: center;
    color: #64748b;
    font-size: 0.9rem;
}

/* Mobile Responsiveness */
@media (max-width: 768px) {
    .header-container {
        flex-direction: column;
        gap: 1rem;
    }

    .nav-list {
        gap: 1rem;
        flex-wrap: wrap;
        justify-content: center;
    }

    .tool-box {
        padding: 1.25rem;
    }
}