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

:root {
    --bg-primary: #0d1117;
    --bg-secondary: #161b22;
    --bg-tertiary: #1c2128;
    --text-primary: #ffffff;
    --text-secondary: #c9d1d9;
    --text-muted: #8b949e;
    --accent-green: #10b981;
    --accent-green-hover: #059669;
    --border-color: #30363d;
    --input-bg: #0d1117;
    --input-border: #30363d;
    --input-focus: #10b981;
    --card-bg: #161b22;
    --shadow: rgba(0, 0, 0, 0.5);
}

body.light-mode {
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-tertiary: #ffffff;
    --text-primary: #1a202c;
    --text-secondary: #4a5568;
    --text-muted: #718096;
    --accent-green: #10b981;
    --accent-green-hover: #059669;
    --border-color: #e2e8f0;
    --input-bg: #ffffff;
    --input-border: #e2e8f0;
    --input-focus: #667eea;
    --card-bg: #ffffff;
    --shadow: rgba(0, 0, 0, 0.1);
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: var(--bg-primary);
    min-height: 100vh;
    color: var(--text-primary);
}

.top-bar {
    background: var(--bg-secondary);
    border-bottom: 1px solid var(--border-color);
    padding: 12px 0;
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(10px);
}

.top-bar-content {
    width: 100%;
    padding: 0 30px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.top-bar-actions {
    display: flex;
    align-items: center;
    gap: 20px;
}

.logo {
    font-size: 1.2em;
    font-weight: 700;
    color: var(--text-primary);
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo-icon {
    display: inline-block;
    width: 40px;
    height: 40px;
    background: var(--bg-tertiary);
    border-radius: 8px;
    padding: 6px;
    flex-shrink: 0;
    object-fit: contain;
}

.logo-text {
    white-space: nowrap;
}

.logo-link {
    text-decoration: none;
    color: inherit;
}

.hidden {
    display: none;
}

.top-bar-btn {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.95em;
    font-weight: 400;
    padding: 4px 0;
    transition: color 0.2s ease;
    background: none;
    border: none;
    cursor: pointer;
}

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

.theme-toggle {
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 8px 12px;
    cursor: pointer;
    color: var(--text-primary);
    font-size: 1.2em;
    display: flex;
    align-items: center;
    justify-content: center;
}

.theme-toggle:hover {
    background: var(--bg-tertiary);
    border-color: var(--accent-green);
}

.theme-icon {
    display: inline-block;
}

body.light-mode .theme-icon {
    content: '☀️';
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 40px 30px;
}

.header {
    text-align: center;
    padding: 40px 0;
}

.header h1 {
    font-size: 3em;
    margin-bottom: 16px;
    font-weight: 700;
    color: var(--text-primary);
    background: linear-gradient(135deg, var(--accent-green) 0%, #3b82f6 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.subtitle {
    font-size: 1.1em;
    color: var(--text-secondary);
    font-weight: 400;
}

.main-content {
    max-width: 900px;
    margin: 0 auto;
}

.form-section {
    margin-bottom: 40px;
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 30px;
    box-shadow: 0 4px 6px var(--shadow);
}

.birthday-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.form-row {
    display: flex;
    gap: 20px;
    align-items: flex-end;
    flex-wrap: wrap;
}

.form-group {
    display: flex;
    flex-direction: column;
    flex: 1;
    min-width: 120px;
    max-width: 100%;
}

.form-group-name {
    flex: 0 0 150px;
}

.form-group-date {
    flex: 1 1 180px;
    min-width: 150px;
}

.form-group-years {
    flex: 1 1 142px;
    min-width: 120px;
}

.form-group.checkbox-group {
    flex: 0 0 auto;
    min-width: auto;
}

.form-group label {
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--text-secondary);
    font-size: 0.9em;
    white-space: nowrap;
}

.label-required {
    color: #ef4444;
    font-weight: 700;
    margin-left: 2px;
}

.label-optional {
    color: var(--text-muted);
    font-weight: 400;
    font-size: 0.85em;
    margin-left: 4px;
    white-space: nowrap;
}

.form-group input[type="text"],
.form-group input[type="number"],
.form-group select {
    padding: 12px;
    background: var(--input-bg);
    border: 2px solid var(--input-border);
    border-radius: 8px;
    font-size: 1em;
    color: var(--text-primary);
    width: 100%;
    height: 48px;
    box-sizing: border-box;
    line-height: 1.5;
}

.form-group select {
    appearance: none;
    -webkit-appearance: none;
    -moz-appearance: none;
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%23c9d1d9' d='M6 9L1 4h10z'/%3E%3C/svg%3E");
    background-repeat: no-repeat;
    background-position: right 12px center;
    background-color: var(--input-bg);
    padding-right: 40px;
    cursor: pointer;
}

body.light-mode .form-group select {
    background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' viewBox='0 0 12 12'%3E%3Cpath fill='%234a5568' d='M6 9L1 4h10z'/%3E%3C/svg%3E");
}

.form-group input[type="text"]:focus,
.form-group input[type="number"]:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--input-focus);
    box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.1);
}

.form-group input[type="text"]::placeholder {
    color: var(--text-muted);
}

.checkbox-group {
    flex-direction: row;
    align-items: center;
    gap: 8px;
}

.checkbox-group label {
    margin-bottom: 0;
    font-weight: normal;
    cursor: pointer;
    color: var(--text-secondary);
}

.checkbox-group input[type="checkbox"] {
    width: 18px;
    height: 18px;
    cursor: pointer;
    accent-color: var(--accent-green);
}

.form-main-layout {
    display: flex;
    gap: 20px;
    align-items: stretch;
}

.form-left-section {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 0;
}

.form-left-section .form-actions {
    margin-top: auto;
    padding-top: 15px;
}

.form-right-section {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 0;
}

.form-right-section.disabled {
    opacity: 0.5;
    pointer-events: none;
}

.form-right-section.disabled input,
.form-right-section.disabled button {
    background-color: #e5e7eb !important;
    color: #9ca3af !important;
    border-color: #d1d5db !important;
    cursor: not-allowed !important;
}

body.light-mode .form-right-section.disabled input,
body.light-mode .form-right-section.disabled button {
    background-color: #f3f4f6 !important;
    color: #9ca3af !important;
    border-color: #e5e7eb !important;
}

.form-right-section .form-actions {
    margin-top: auto;
    padding-top: 15px;
}

.form-download-section {
    display: flex;
    gap: 15px;
    align-items: flex-end;
    margin-bottom: 20px;
}

.form-actions {
    display: flex;
    gap: 15px;
    margin-top: 0;
}

.btn {
    padding: 14px 28px;
    border: none;
    border-radius: 8px;
    font-size: 1em;
    font-weight: 600;
    cursor: pointer;
    flex: 1;
}

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

.btn-primary:hover:not(:disabled) {
    background: var(--accent-green-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(16, 185, 129, 0.4);
}

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

.btn-secondary:hover:not(:disabled) {
    background: var(--bg-secondary);
    border-color: var(--accent-green);
    transform: translateY(-2px);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none !important;
}

.results-section {
    margin-top: 40px;
    padding-top: 40px;
    border-top: 1px solid var(--border-color);
}

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

.results-table-container {
    overflow-x: auto;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    background: var(--card-bg);
}

.results-table {
    width: 100%;
    border-collapse: collapse;
    background: var(--card-bg);
}

.results-table thead {
    background: var(--bg-secondary);
}

.results-table th {
    padding: 15px;
    text-align: left;
    font-weight: 600;
    color: var(--text-primary);
    border-bottom: 1px solid var(--border-color);
}

.results-table td {
    padding: 15px;
    border-bottom: 1px solid var(--border-color);
    color: var(--text-secondary);
}

.results-table tbody tr:hover {
    background: var(--bg-tertiary);
}

.results-table tbody tr:last-child td {
    border-bottom: none;
}

.footer {
    margin-top: 60px;
    padding: 20px;
    text-align: center;
    color: var(--text-muted);
    font-size: 0.9em;
    border-top: 1px solid var(--border-color);
}

.footer p {
    margin: 8px 0;
}

.footer-contact {
    font-size: 0.85em;
    margin-top: 12px;
}

.footer-contact a {
    color: var(--accent-green);
    text-decoration: none;
    transition: color 0.2s ease;
}

.footer-contact a:hover {
    color: var(--accent-green-hover);
    text-decoration: underline;
}

@media (max-width: 1024px) {
    .form-main-layout {
        flex-direction: column;
        gap: 30px;
    }

    .form-left-section {
        width: 100%;
    }

    .form-left-section .form-actions {
        margin-top: 15px;
        padding-top: 0;
    }

    .form-right-section {
        width: 100%;
    }

    .form-right-section .form-actions {
        margin-top: 15px;
        padding-top: 0;
    }
}

@media (max-width: 768px) {
    .header h1 {
        font-size: 2em;
    }

    .subtitle {
        font-size: 1em;
        padding: 0 10px;
    }

    .form-row {
        flex-direction: column;
        gap: 15px;
        align-items: stretch;
    }

    .form-group {
        min-width: 100%;
        width: 100%;
    }

    .form-group-name,
    .form-group-date,
    .form-group-years {
        flex: 1 1 100%;
        min-width: 100%;
    }

    .checkbox-group {
        align-self: flex-start;
    }

    .form-actions {
        flex-direction: column;
        width: 100%;
    }

    .btn {
        width: 100%;
    }

    .form-section {
        padding: 20px;
    }

    .main-content {
        padding: 20px;
    }

    .container {
        padding: 20px 15px;
    }

    .top-bar-content {
        padding: 0 15px;
    }

    .logo {
        font-size: 1em;
    }

    .results-section {
        margin-top: 30px;
        padding-top: 30px;
    }

    .results-table-container {
        overflow-x: auto;
    }
}

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

    .subtitle {
        font-size: 0.9em;
    }

    .form-section {
        padding: 15px;
    }

    .container {
        padding: 15px 10px;
    }

    .top-bar-content {
        padding: 0 10px;
    }
}

.loading {
    text-align: center;
    padding: 20px;
    color: var(--accent-green);
    font-weight: 600;
}

.error {
    background: rgba(239, 68, 68, 0.1);
    color: #fca5a5;
    padding: 15px;
    border-radius: 8px;
    margin-top: 20px;
    border: 1px solid rgba(239, 68, 68, 0.3);
}

body.light-mode .error {
    background: #fee2e2;
    color: #991b1b;
    border-color: #fecaca;
}

/* FAQ 페이지 스타일 */
.faq-section {
    display: flex;
    flex-direction: column;
    gap: 20px;
    margin-bottom: 40px;
}

.faq-item {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 24px;
    box-shadow: 0 2px 4px var(--shadow);
    transition: box-shadow 0.2s ease, border-color 0.2s ease;
}

.faq-item:hover {
    box-shadow: 0 4px 8px var(--shadow);
    border-color: var(--accent-green);
}

.faq-question {
    display: flex;
    align-items: flex-start;
    gap: 8px;
    margin-bottom: 16px;
    font-weight: 600;
    color: var(--text-primary);
    font-size: 1.1em;
    line-height: 1.5;
}

.faq-question strong {
    color: var(--accent-green);
    font-weight: 600;
    margin-right: 0;
    flex-shrink: 0;
}

.faq-answer {
    color: var(--text-secondary);
    line-height: 1.8;
    padding-left: 0;
}

.faq-answer strong {
    color: var(--accent-green);
    font-weight: 600;
    margin-right: 8px;
}

.faq-answer p {
    margin: 0;
    display: inline;
}

.faq-back-link {
    text-align: center;
    margin-top: 40px;
    padding-top: 40px;
    border-top: 1px solid var(--border-color);
}

.faq-back-link .btn {
    max-width: 300px;
}

@media (max-width: 768px) {
    .faq-item {
        padding: 20px;
    }

    .faq-question {
        font-size: 1em;
    }

    .faq-answer {
        padding-left: 0;
    }
}