html {
    box-sizing: border-box;
}

*, *:before, *:after {
    box-sizing: inherit;
}

@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+KR:wght@400;700&display=swap');

:root {
    --bg-color: #f0f4f8;
    --text-color: #333;
    --text-color-light: #7f8c8d;
    --header-bg: white;
    --container-bg: white;
    --h1-color: #2c3e50;
    --btn-bg: #ecf0f1;
    --btn-active-bg: #3498db;
    --btn-active-text: white;
    --btn-active-border: #2980b9;
    --result-bg: #fafafa;
    --result-border: #ddd;
    --result-h2-color: #3498db;
    --footer-text: #7f8c8d;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --link-color: #3498db;
    --link-hover-color: #2980b9;
}

body.dark-mode {
    --bg-color: #2c3e50;
    --text-color: #ecf0f1;
    --text-color-light: #bdc3c7;
    --header-bg: #34495e;
    --container-bg: #34495e;
    --h1-color: #ecf0f1;
    --btn-bg: #2c3e50;
    --btn-active-bg: #3498db;
    --result-bg: #2c3e50;
    --result-border: #7f8c8d;
    --result-h2-color: #3498db;
    --footer-text: #bdc3c7;
    --shadow-color: rgba(0, 0, 0, 0.4);
    --link-color: #5dade2;
    --link-hover-color: #85c1e9;
}

body {
    font-family: 'Noto Sans KR', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    margin: 0;
    padding-top: 80px; /* Space for fixed header */
    transition: background-color 0.3s, color 0.3s;
}

/* Header and Navigation */
.site-header {
    background-color: var(--header-bg);
    box-shadow: 0 2px 10px var(--shadow-color);
    padding: 0 2rem;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 70px;
    transition: background-color 0.3s;
}

.site-nav {
    display: flex;
    align-items: center;
    gap: 2rem;
}

.nav-logo {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--h1-color);
    text-decoration: none;
}

.site-nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    gap: 1.5rem;
}

.site-nav a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 700;
    transition: color 0.2s;
}

.site-nav a:hover {
    color: var(--link-hover-color);
}

#theme-toggle {
    background: transparent;
    border: none;
    cursor: pointer;
    font-size: 1.5rem;
    color: var(--text-color);
}

/* Main Content Area */
.container {
    background-color: var(--container-bg);
    padding: 2rem 3rem;
    border-radius: 15px;
    box-shadow: 0 10px 25px var(--shadow-color);
    text-align: center;
    width: 90%;
    max-width: 700px; /* Increased width slightly */
    margin: 2rem auto; /* Centered with margin */
    transition: background-color 0.3s;
}

.page-container {
    text-align: left;
}

h1 {
    color: var(--h1-color);
    margin-bottom: 1rem;
    text-align: center;
}

p, .intro-text {
    color: var(--text-color-light);
    margin-bottom: 2rem;
    line-height: 1.7;
}

.duration-selector {
    margin-bottom: 2rem;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 10px;
}

.duration-btn {
    background-color: var(--btn-bg);
    color: var(--text-color);
    border: 2px solid transparent;
    padding: 10px 20px;
    border-radius: 25px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 700;
    transition: all 0.3s ease;
}

.duration-btn:hover {
    opacity: 0.8;
}

.duration-btn.active {
    background-color: var(--btn-active-bg);
    color: var(--btn-active-text);
    border-color: var(--btn-active-border);
}

#generate-btn {
    background: linear-gradient(45deg, #f1c40f, #f39c12);
    color: white;
    border: none;
    padding: 15px 30px;
    border-radius: 30px;
    cursor: pointer;
    font-size: 1.2rem;
    font-weight: 700;
    letter-spacing: 1px;
    box-shadow: 0 4px 15px rgba(243, 156, 18, 0.4);
    transition: all 0.3s ease;
    margin-bottom: 2rem;
}

#generate-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(243, 156, 18, 0.6);
}

#result {
    background-color: var(--result-bg);
    border: 1px dashed var(--result-border);
    border-radius: 10px;
    padding: 1.5rem;
    min-height: 150px;
    text-align: center;
    line-height: 1.8;
    color: var(--text-color);
    transition: background-color 0.3s, border-color 0.3s;
}

#result h2 {
    color: var(--result-h2-color);
    margin-bottom: 1rem;
    border-bottom: 2px solid var(--result-h2-border);
    padding-bottom: 0.5rem;
}

/* Form Styling */
.contact-form, .text-content {
    margin-top: 2rem;
}

.text-content h2 {
    color: var(--h1-color);
    margin-top: 2rem;
}

.text-content ul {
    padding-left: 20px;
}
.text-content li {
    margin-bottom: 1rem;
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.contact-form label {
    font-weight: 700;
    color: var(--text-color);
    margin-bottom: 0.2rem;
}

.contact-form input[type="text"],
.contact-form input[type="email"],
.contact-form textarea {
    padding: 0.8rem;
    border: 1px solid var(--result-border);
    border-radius: 8px;
    font-size: 1rem;
    background-color: var(--result-bg);
    color: var(--text-color);
    transition: border-color 0.3s, background-color 0.3s;
}

.contact-form input[type="text"]:focus,
.contact-form input[type="email"]:focus,
.contact-form textarea:focus {
    border-color: var(--btn-active-bg);
    outline: none;
}

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

.submit-btn {
    background-color: #2ecc71;
    color: white;
    border: none;
    padding: 1rem 1.5rem;
    border-radius: 25px;
    cursor: pointer;
    font-size: 1.1rem;
    font-weight: 700;
    margin-top: 1rem;
    transition: background-color 0.3s ease;
}

.submit-btn:hover {
    background-color: #27ae60;
}

/* Footer */
.site-footer-main {
    text-align: center;
    padding: 2rem;
    margin-top: 2rem;
    color: var(--footer-text);
}

.site-footer-main a {
    color: var(--footer-text);
    text-decoration: none;
}

.site-footer-main a:hover {
    text-decoration: underline;
}

.visitor-counter {
    margin-bottom: 1rem;
    font-size: 0.9em;
    color: var(--text-color-light);
}

.visitor-counter #visitor-count {
    font-weight: 700;
}

/* Loader Animation */
.loader {
    border: 5px solid var(--btn-bg);
    border-top: 5px solid var(--btn-active-bg);
    border-radius: 50%;
    width: 50px;
    height: 50px;
    animation: spin 1s linear infinite;
    margin: 2rem auto;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

/* Summary Paragraph */
.summary {
    text-align: left;
    margin-top: 1.5rem;
    margin-bottom: 1.5rem;
    padding: 1rem;
    background-color: var(--bg-color);
    border-radius: 8px;
    color: var(--text-color);
    line-height: 1.8;
}