:root {
    --primary-color: #2B2D42;
    --accent-color: #FF4D6D;
    --background-light: #F8F9FA;
    --background-dark: #1A1B1E;
    --text-light: #2B2D42;
    --text-dark: #E9ECEF;
    --card-shadow: 5px 5px 0px #000;
    --card-border: 3px solid #000;
    --secondary-text-light: #666;
    --secondary-text-dark: #A0A0A0;
}

[data-theme="dark"] {
    --primary-color: #FF4D6D;
    --background-color: var(--background-dark);
    --text-color: var(--text-dark);
    --card-background: #2B2D42;
    --secondary-text: var(--secondary-text-dark);
    --link-color: #66B2FF;
    --border-color: #444;
    --header-text-color: #FFFFFF;
    --header-shadow-color: #FF6B6B;
}

[data-theme="light"] {
    --primary-color: #2B2D42;
    --background-color: var(--background-light);
    --text-color: var(--text-light);
    --card-background: #ffffff;
    --secondary-text: var(--secondary-text-light);
    --link-color: #1976d2;
    --border-color: #000;
    --header-text-color: var(--primary-color);
    --header-shadow-color: var(--accent-color);
}

body {
    font-family: 'Space Grotesk', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    margin: 0;
    padding: 20px;
    background-color: var(--background-color);
    color: var(--text-color);
    transition: background-color 0.3s ease, color 0.3s ease;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

 .header {
    text-align: center;
    margin-bottom: 40px;
    position: relative;
}

.header h1 {
    font-size: 3em;
    font-weight: 800;
    color: var(--header-text-color);
    margin: 0;
    letter-spacing: -0.03em;
    text-shadow: 3px 3px 0px var(--header-shadow-color);
}

.theme-toggle {
    position: fixed;
    top: 20px;
    right: 20px;
    padding: 10px;
    border: 2px solid #000;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    cursor: pointer;
    background-color: var(--background-light);
    box-shadow: 3px 3px 0px #000;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    justify-content: center;
}

.theme-toggle:hover {
    transform: translate(-2px, -2px);
    box-shadow: 5px 5px 0px #000;
}

.filters {
    margin-bottom: 30px;
    display: flex;
    gap: 15px;
    justify-content: center;
    flex-wrap: wrap;
    padding: 10px;
}

 .filter-btn {
    padding: 12px 24px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    background-color: var(--card-background);
    color: var(--text-color);
    cursor: pointer;
    transition: all 0.2s ease;
    font-weight: 600;
    font-size: 1rem;
    box-shadow: 3px 3px 0px var(--border-color);
    position: relative;
    top: 0;
    left: 0;
}

.filter-btn:hover {
    transform: translate(-2px, -2px);
    box-shadow: 5px 5px 0px #000;
}

.filter-btn.active {
    background-color: var(--accent-color);
    color: white;
    border-color: #000;
}

.filter-btn:active {
    transform: translate(2px, 2px);
    box-shadow: 1px 1px 0px #000;
}

 .contest-grid {
     display: grid;
     grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
     gap: 20px;
 }

 .contest-card {
    position: relative;
    background: var(--card-background);
    border: 2px solid var(--border-color);
    border-radius: 8px;
    padding: 25px;
    box-shadow: 5px 5px 0px var(--border-color);
    transition: all 0.2s ease;
    transform: translate(0, 0);
}

.contest-card:hover {
    transform: translate(-2px, -2px);
    box-shadow: 7px 7px 0px var(--border-color);
}

.contest-name {
    font-size: 1.4em;
    font-weight: 700;
    margin-bottom: 15px;
    color: var(--text-color);
    letter-spacing: -0.02em;
}

.contest-time,
.contest-duration {
    color: var(--secondary-text);
    margin-bottom: 5px;
    font-weight: 500;
}

.copy-btn {
    position: absolute;
    top: 10px;
    right: 10px;
    background: var(--card-background);
    border: 2px solid var(--border-color);
    border-radius: 4px;
    padding: 5px 8px;
    cursor: pointer;
    transition: all 0.3s;
}

.copy-btn:hover {
    background: #f0f0f0;
    transform: scale(1.05);
}

.contest-link {
    display: inline-block;
    margin-top: 10px;
    color: var(--link-color);
    text-decoration: none;
    font-weight: 500;
    transition: all 0.2s ease;
}

.contest-link:hover {
    text-decoration: underline;
    opacity: 0.9;
}

.update-time {
    text-align: center;
    color: var(--secondary-text);
    margin-top: 20px;
    font-size: 0.9em;
    padding: 10px;
    border-top: 1px solid var(--border-color);
}

 /* 新增模态框样式 */
.modal-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background-color: rgba(0, 0, 0, 0.5);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
}

.modal-content {
    background: white;
    padding: 30px;
    border-radius: 8px;
    max-width: 500px;
    width: 90%;
    position: relative;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.15);
}

.modal-close {
    position: absolute;
    top: 15px;
    right: 15px;
    background: none;
    border: none;
    font-size: 1.5em;
    cursor: pointer;
    color: #666;
}

.modal-title {
    margin-top: 0;
    margin-bottom: 20px;
    color: #333;
}

.modal-info p {
    margin-bottom: 15px;
    line-height: 1.6;
}

.modal-link {
    display: inline-block;
    margin-top: 20px;
    color: #1976d2;
    text-decoration: none;
}

.modal-link:hover {
    text-decoration: underline;
}

 @media (max-width: 768px) {
   .footer {
     padding: 15px 0;
     font-size: 0.8em;
   }
   .container {
     padding: 10px;
   }

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

   .filters {
     gap: 12px;
     flex-wrap: wrap;
   }

   @media (max-width: 768px) {
     .filter-btn {
       padding: 12px 20px;
       min-width: 110px;
       margin: 6px;
       font-size: 0.9em;
     }
   
     .contest-card {
    position: relative;

       margin: 0 8px 15px 8px;
       padding: 16px;
     }
   }
   .contest-name {
     font-size: 1.1em;
   }
 }