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

:root {
    --primary-color: #3b82f6;
    --primary-hover: #2563eb;
    --secondary-color: #10b981;
    --danger-color: #ef4444;
    --text-primary: #1f2937;
    --text-secondary: #6b7280;
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-tertiary: #f3f4f6;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --border-radius: 12px;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen',
        'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue',
        sans-serif;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    line-height: 1.6;
}

/* Navigation Bar */
.navbar {
    background-color: white;
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 64px;
}

.logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
    text-decoration: none;
    transition: opacity 0.3s ease;
}

.logo:hover {
    opacity: 0.8;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 8px;
    margin: 0;
    padding: 0;
}

.nav-item {
    margin: 0;
}

.nav-link {
    display: block;
    padding: 10px 20px;
    color: var(--text-primary);
    text-decoration: none;
    font-weight: 500;
    border-radius: 8px;
    transition: all 0.3s ease;
}

.nav-link:hover {
    background-color: var(--bg-tertiary);
    color: var(--primary-color);
}

.nav-link.active {
    background-color: var(--primary-color);
    color: white;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
}

/* Header */
header {
    text-align: center;
    margin-bottom: 40px;
    padding: 40px 20px 20px;
}

header h1 {
    font-size: 2.5rem;
    color: var(--text-primary);
    margin-bottom: 10px;
}

.subtitle {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

/* Calculator Card */
.calculator-card {
    background: var(--bg-primary);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-lg);
    padding: 30px;
    margin-bottom: 30px;
}

/* Tab Guide */
.tab-guide {
    text-align: center;
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 20px;
    padding: 15px 20px;
    background: linear-gradient(135deg, #f0f9ff 0%, #e0f2fe 100%);
    border-radius: 10px;
    border-left: 4px solid var(--primary-color);
}

.guide-hint {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--text-secondary);
    display: inline-block;
    margin-left: 8px;
}

/* Tabs */
.tabs {
    display: flex;
    gap: 12px;
    margin-bottom: 30px;
    background-color: var(--bg-secondary);
    padding: 8px;
    border-radius: var(--border-radius);
}

.tab-btn {
    flex: 1;
    padding: 16px 20px;
    background: white;
    border: 2px solid var(--border-color);
    border-radius: 10px;
    color: var(--text-secondary);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.tab-btn:hover {
    color: var(--primary-color);
    background-color: rgba(59, 130, 246, 0.05);
    border-color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(59, 130, 246, 0.2);
}

.tab-btn.active {
    color: white;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-hover) 100%);
    border-color: var(--primary-color);
    box-shadow: 0 4px 12px rgba(59, 130, 246, 0.3);
    transform: translateY(-2px);
}

/* Tab Content */
.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Input Group */
.input-group {
    margin-bottom: 30px;
}

.input-group label {
    display: block;
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 10px;
}

.input-wrapper {
    position: relative;
    display: flex;
    align-items: center;
}

.input-wrapper input {
    width: 100%;
    padding: 16px 50px 16px 20px;
    font-size: 1.5rem;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    outline: none;
    transition: all 0.3s ease;
    text-align: right;
}

.input-wrapper input:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.input-wrapper .unit {
    position: absolute;
    right: 20px;
    font-size: 1.2rem;
    color: var(--text-secondary);
    pointer-events: none;
}

/* Calculation Divider */
.calculation-divider {
    width: 100%;
    height: 2px;
    background: linear-gradient(90deg, transparent, var(--border-color) 20%, var(--border-color) 80%, transparent);
    margin: 30px 0;
}

/* Result Group */
.result-group {
    background-color: var(--bg-secondary);
    border-radius: var(--border-radius);
    padding: 20px;
    margin-bottom: 20px;
}

.result-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 0;
    border-bottom: 1px solid var(--border-color);
}

.result-item:last-child {
    border-bottom: none;
}

.result-item.total {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    margin: 10px -20px -20px;
    padding: 20px;
    border-radius: 0 0 var(--border-radius) var(--border-radius);
    color: white;
}

.result-item .label {
    font-size: 1rem;
    font-weight: 500;
    color: var(--text-secondary);
}

.result-item.total .label {
    color: white;
    font-size: 1.1rem;
}

.result-item .value {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
}

.result-item.total .value {
    color: white;
    font-size: 1.8rem;
}

/* Buttons */
.btn-calculate {
    width: 100%;
    padding: 18px;
    font-size: 1.2rem;
    font-weight: 600;
    color: white;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-hover) 100%);
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: var(--shadow-md);
}

.btn-calculate:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-calculate:active {
    transform: translateY(0);
}


/* Info Section */
.info-section {
    background: var(--bg-primary);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
    padding: 30px;
    margin-bottom: 30px;
}

.info-section h2 {
    font-size: 1.8rem;
    margin-bottom: 20px;
    color: var(--text-primary);
}

.info-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
}

.info-card {
    padding: 20px;
    background-color: var(--bg-secondary);
    border-radius: 8px;
    border-left: 4px solid var(--primary-color);
}

.info-card h3 {
    font-size: 1.2rem;
    margin-bottom: 10px;
    color: var(--primary-color);
}

.info-card p {
    color: var(--text-secondary);
    margin-bottom: 10px;
}

.info-card ul {
    list-style: none;
    padding-left: 0;
}

.info-card ul li {
    padding: 5px 0;
    color: var(--text-secondary);
}

.info-card ul li::before {
    content: "✓ ";
    color: var(--secondary-color);
    font-weight: bold;
    margin-right: 8px;
}

/* CTA Section */
.cta-section {
    margin-bottom: 30px;
}

.cta-card {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 40px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-lg);
    text-align: center;
}

.cta-card-full {
    width: 100%;
}

.cta-card h3 {
    font-size: 1.3rem;
    margin-bottom: 10px;
}

.cta-card p {
    margin-bottom: 20px;
    opacity: 0.9;
}

.btn-cta {
    display: inline-block;
    padding: 12px 30px;
    background-color: white;
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    border-radius: 8px;
    transition: all 0.3s ease;
}

.btn-cta:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.2);
}

/* Partnership Link */
.partnership-link {
    color: var(--primary-color);
    text-decoration: none;
    font-weight: 600;
    transition: color 0.3s ease;
}

.partnership-link:hover {
    color: var(--primary-hover);
    text-decoration: underline;
}

/* Partnership Form Container */
.partnership-form-container {
    background: var(--bg-secondary);
    border-radius: var(--border-radius);
    padding: 30px;
    margin: 20px 0;
    border: 2px solid var(--border-color);
}

.partnership-description {
    color: var(--text-secondary);
    text-align: center;
    margin-bottom: 20px;
    font-size: 0.95rem;
}

.contact-email {
    margin-top: 10px;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.partnership-form {
    max-width: 600px;
    margin: 0 auto;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    font-size: 1rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 14px 16px;
    font-size: 1rem;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    outline: none;
    transition: all 0.3s ease;
    font-family: inherit;
    background-color: var(--bg-primary);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

.form-group input:focus,
.form-group textarea:focus {
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.btn-submit {
    width: 100%;
    padding: 16px;
    font-size: 1.1rem;
    font-weight: 600;
    color: white;
    background: linear-gradient(135deg, var(--primary-color) 0%, var(--primary-hover) 100%);
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    box-shadow: var(--shadow-md);
}

.btn-submit:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-submit:active {
    transform: translateY(0);
}

.btn-submit:disabled {
    opacity: 0.6;
    cursor: not-allowed;
    transform: none;
}

.form-message {
    margin-top: 20px;
    padding: 15px;
    border-radius: 8px;
    text-align: center;
    font-weight: 500;
    display: none;
}

.form-message.success {
    display: block;
    background-color: #d1fae5;
    color: #065f46;
    border: 1px solid #6ee7b7;
}

.form-message.error {
    display: block;
    background-color: #fee2e2;
    color: #991b1b;
    border: 1px solid #fca5a5;
}

/* Footer */
footer {
    text-align: center;
    padding: 40px 20px;
    color: var(--text-secondary);
    font-size: 0.9rem;
}

footer p {
    margin-bottom: 10px;
}

.copyright {
    margin-top: 20px;
    font-size: 0.85rem;
}

.footer-links {
    display: flex;
    justify-content: center;
    gap: 20px;
    margin-top: 15px;
}

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-links a:hover {
    color: var(--primary-color);
}

/* Mobile break - 데스크톱에서는 숨김 */
.mobile-break {
    display: none;
}

/* Responsive Design */
@media (max-width: 768px) {
    /* 모바일에서만 줄바꿈 표시 */
    .mobile-break {
        display: inline;
    }

    .nav-container {
        height: auto;
        padding: 12px 15px;
        flex-direction: column;
        gap: 12px;
    }

    .logo {
        font-size: 1.3rem;
    }

    .nav-menu {
        width: 100%;
        flex-direction: column;
        gap: 8px;
    }

    .nav-link {
        text-align: center;
        padding: 12px 16px;
    }

    .container {
        padding: 15px;
    }

    header {
        padding: 20px 10px 10px;
    }

    header h1 {
        font-size: 1.8rem;
        word-break: keep-all;
    }

    .subtitle {
        font-size: 0.95rem;
        word-break: keep-all;
    }

    .calculator-card {
        padding: 20px 15px;
    }

    .tab-guide {
        font-size: 1rem;
        padding: 12px 15px;
        margin-bottom: 15px;
    }

    .guide-hint {
        display: block;
        margin-top: 5px;
        margin-left: 0;
        font-size: 0.85rem;
    }

    .tabs {
        flex-direction: column;
        gap: 8px;
        padding: 6px;
    }

    .tab-btn {
        padding: 14px 15px;
        font-size: 0.95rem;
        word-break: keep-all;
        text-align: center;
    }

    .tab-btn.active {
        box-shadow: 0 2px 8px rgba(59, 130, 246, 0.3);
    }

    .input-group label {
        font-size: 0.95rem;
    }

    .input-wrapper input {
        font-size: 1.1rem;
        padding: 14px 45px 14px 12px;
    }

    .input-wrapper .unit {
        right: 12px;
        font-size: 1rem;
    }

    .result-item {
        padding: 12px 0;
    }

    .result-item .label {
        font-size: 0.9rem;
        word-break: keep-all;
    }

    .result-item .value {
        font-size: 1.1rem;
        word-break: break-all;
    }

    .result-item.total {
        padding: 15px;
        margin: 10px -15px -15px;
    }

    .result-item.total .label {
        font-size: 1rem;
    }

    .result-item.total .value {
        font-size: 1.4rem;
    }

    .btn-calculate {
        font-size: 1.1rem;
        padding: 16px;
    }

    .info-section {
        padding: 20px 15px;
    }

    .info-section h2 {
        font-size: 1.5rem;
        word-break: keep-all;
    }

    .info-grid {
        grid-template-columns: 1fr;
        gap: 15px;
    }

    .info-card {
        padding: 15px;
    }

    .info-card h3 {
        font-size: 1.1rem;
        word-break: keep-all;
    }

    .info-card p,
    .info-card ul li {
        font-size: 0.9rem;
        word-break: keep-all;
    }

    .cta-card {
        padding: 30px 20px;
    }

    .cta-card h3 {
        font-size: 1.15rem;
        word-break: keep-all;
    }

    .cta-card p {
        font-size: 0.9rem;
        word-break: keep-all;
    }

    .partnership-form-container {
        padding: 20px 15px;
    }

    .partnership-description {
        font-size: 0.9rem;
        word-break: keep-all;
    }

    .contact-email {
        font-size: 0.85rem;
    }

    .form-group label {
        font-size: 0.95rem;
    }

    .form-group input,
    .form-group textarea {
        font-size: 0.95rem;
        padding: 12px 14px;
    }

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

    footer {
        padding: 30px 15px;
        font-size: 0.85rem;
    }

    footer p {
        word-break: keep-all;
    }

    .footer-links {
        flex-direction: column;
        gap: 10px;
    }
}

@media (max-width: 480px) {
    header h1 {
        font-size: 1.5rem;
    }

    .subtitle {
        font-size: 0.9rem;
    }

    .calculator-card {
        padding: 15px 12px;
    }

    .tab-btn {
        font-size: 0.9rem;
        padding: 12px 12px;
    }

    .tab-btn.active {
        box-shadow: 0 2px 6px rgba(59, 130, 246, 0.25);
    }

    .input-group label {
        font-size: 0.9rem;
    }

    .input-wrapper input {
        font-size: 1rem;
        padding: 12px 40px 12px 10px;
    }

    .input-wrapper .unit {
        right: 10px;
        font-size: 0.9rem;
    }

    .result-item .label {
        font-size: 0.85rem;
    }

    .result-item .value {
        font-size: 1rem;
    }

    .result-item.total {
        padding: 12px;
    }

    .result-item.total .label {
        font-size: 0.95rem;
    }

    .result-item.total .value {
        font-size: 1.25rem;
    }

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

    .info-section h2 {
        font-size: 1.3rem;
    }

    .info-card h3 {
        font-size: 1rem;
    }

    .info-card p,
    .info-card ul li {
        font-size: 0.85rem;
    }

    .cta-card {
        padding: 20px 15px;
    }

    .cta-card h3 {
        font-size: 1.05rem;
    }

    .cta-card p {
        font-size: 0.85rem;
    }

    .btn-cta {
        padding: 10px 24px;
        font-size: 0.9rem;
    }

    .partnership-form-container {
        padding: 15px 12px;
    }

    .partnership-description {
        font-size: 0.85rem;
    }

    .contact-email {
        font-size: 0.8rem;
    }

    .form-group label {
        font-size: 0.9rem;
    }

    .form-group input,
    .form-group textarea {
        font-size: 0.9rem;
        padding: 12px;
    }

    .btn-submit {
        font-size: 0.95rem;
        padding: 13px;
    }

    .form-message {
        font-size: 0.9rem;
        padding: 12px;
    }
}