:root {
    --bg-color: #f8f9fa;
    --text-color: #212529;
    --container-bg: #ffffff;
    --h1-color: #212529;
    --h1-shadow: rgba(0, 0, 0, 0.05);
    --button-bg: #4dabf7;
    --button-hover: #339af0;
    --button-shadow: rgba(77, 171, 247, 0.3);
    --number-bg: #e9ecef;
    --number-text: #495057;
    --toggle-bg: #dee2e6;
}

[data-theme="dark"] {
    --bg-color: #1a1b1e;
    --text-color: #f8f9fa;
    --container-bg: #25262b;
    --h1-color: #ffffff;
    --h1-shadow: rgba(255, 255, 255, 0.1);
    --button-bg: #5c7cfa;
    --button-hover: #4c6ef5;
    --button-shadow: rgba(92, 124, 250, 0.4);
    --number-bg: #373a40;
    --number-text: #ced4da;
    --toggle-bg: #373a40;
}

* {
    transition: background-color 0.3s ease, color 0.3s ease, border-color 0.3s ease, box-shadow 0.3s ease;
}

body {
    font-family: 'Pretendard', -apple-system, BlinkMacSystemFont, system-ui, Roboto, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
}

.container {
    text-align: center;
    padding: 2rem;
    background-color: var(--container-bg);
    border-radius: 20px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.05);
    max-width: 600px;
    width: 90%;
}

.partnership {
    margin-top: 3rem;
    padding-top: 2rem;
    border-top: 1px solid var(--toggle-bg);
}

.partnership h2 {
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    color: var(--text-color);
}

.form-group {
    margin-bottom: 1rem;
}

.partnership input, 
.partnership textarea {
    width: 100%;
    padding: 12px;
    border-radius: 8px;
    border: 1px solid var(--toggle-bg);
    background-color: var(--bg-color);
    color: var(--text-color);
    font-family: inherit;
    box-sizing: border-box;
}

.partnership textarea {
    height: 100px;
    resize: vertical;
}

.partnership button[type="submit"] {
    width: 100%;
    padding: 12px;
    border-radius: 8px;
    border: none;
    background-color: var(--button-bg);
    color: #ffffff;
    font-weight: 700;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

.partnership button[type="submit"]:hover {
    background-color: var(--button-hover);
}

h1 {
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 2rem;
    color: var(--h1-color);
    text-shadow: 0 2px 4px var(--h1-shadow);
}

#theme-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    padding: 12px 24px;
    border-radius: 30px;
    border: none;
    background-color: var(--toggle-bg);
    color: var(--text-color);
    cursor: pointer;
    font-weight: 700;
    display: flex;
    align-items: center;
    gap: 8px;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
    font-size: 1rem;
}

#theme-toggle:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 16px rgba(0, 0, 0, 0.15);
}

#theme-toggle:active {
    transform: translateY(0);
}