:root {
    --bg-color: #000000;
    --text-primary: #ffffff;
    --text-secondary: #aaaaaa;
    --border-color: rgba(255, 255, 255, 0.1);
    --accent-color: #ffffff;
    --glass-bg: rgba(255, 255, 255, 0.03);
    --acrylic-bg: rgba(20, 20, 20, 0.6);
    --blur-val: 20px;
    --transition-fast: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 0.6s cubic-bezier(0.77, 0, 0.175, 1);
}

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

body {
    font-family: 'Share Tech Mono', 'Noto Sans SC', sans-serif;
    background-color: var(--bg-color);
    background-image: radial-gradient(circle at 50% 50%, #111 0%, #000 100%);
    color: var(--text-primary);
    height: 100vh;
    overflow: hidden;
    -webkit-font-smoothing: antialiased;
}

.global-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 60px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 0 30px;
    z-index: 1000;
    background: var(--glass-bg);
    backdrop-filter: blur(var(--blur-val));
    -webkit-backdrop-filter: blur(var(--blur-val));
    border-bottom: 1px solid var(--border-color);
}

.home-icon-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    padding: 10px 0;
    font-family: inherit;
    font-size: 0.9rem;
    cursor: pointer;
    letter-spacing: 4px;
    transition: var(--transition-fast);
    display: flex;
    align-items: center;
    position: relative;
    font-weight: 700;
}

.home-icon-btn::before {
    content: '[';
    margin-right: 8px;
    opacity: 0;
    transition: var(--transition-fast);
}

.home-icon-btn::after {
    content: ']';
    margin-left: 8px;
    opacity: 0;
    transition: var(--transition-fast);
}

.home-icon-btn:hover {
    color: var(--text-primary);
    background: transparent;
}

.home-icon-btn:hover::before,
.home-icon-btn:hover::after {
    opacity: 1;
}

.brand-title {
    font-size: 1.2rem;
    font-weight: 700;
    letter-spacing: 4px;
    text-transform: uppercase;
}

#app-container {
    display: flex;
    width: 100vw;
    height: calc(100vh - 60px);
    margin-top: 60px;
}

.sidebar {
    width: 120px;
    height: 100%;
    border-right: 1px solid var(--border-color);
    background: var(--acrylic-bg);
    backdrop-filter: blur(var(--blur-val));
    -webkit-backdrop-filter: blur(var(--blur-val));
    z-index: 100;
}

.year-nav {
    height: 100%;
    overflow-y: auto;
    scrollbar-width: none; /* Firefox */
}

.year-nav::-webkit-scrollbar {
    display: none; /* Chrome/Safari */
}

.year-list {
    list-style: none;
    padding: 20px 0;
}

.year-item {
    padding: 25px 0;
    cursor: pointer;
    font-size: 1.1rem;
    color: var(--text-secondary);
    transition: var(--transition-fast);
    text-align: center;
    letter-spacing: 2px;
    border-bottom: 1px solid transparent;
}

.year-item:hover, .year-item.active {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
}

.year-item.active {
    border-right: 2px solid var(--text-primary);
}

.content-area {
    flex-grow: 1;
    position: relative;
    overflow: hidden;
}

.view {
    position: absolute;
    inset: 0;
    display: flex;
    flex-direction: column;
    background-color: transparent;
    visibility: hidden;
    opacity: 0;
    transition: opacity var(--transition-fast), visibility var(--transition-fast);
}

.view.active {
    visibility: visible;
    opacity: 1;
}

#home-view {
    position: absolute;
    top: -60px;
    left: 0;
    width: 100%;
    height: 100vh;
    z-index: 50;
    display: flex;
    justify-content: center;
    align-items: center;
    pointer-events: none;
}

#home-view.active {
    pointer-events: all;
}

.center-content {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100%;
    height: 100%;
}

.home-decor {
    position: absolute;
    color: var(--text-secondary);
    font-size: 0.75rem;
    letter-spacing: 2px;
    opacity: 0.4;
    pointer-events: none;
}

.decor-top-left { top: 40px; left: 60px; }
.decor-top-right { top: 40px; right: 60px; }
.decor-bottom-left { bottom: 40px; left: 60px; }
.decor-bottom-right { bottom: 40px; right: 60px; }

.decor-center-line {
    top: 50%;
    left: 0;
    width: 100%;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--border-color), transparent);
    transform: translateY(-50%);
    opacity: 0.2;
}

.main-enter-btn {
    position: relative;
    background: transparent;
    border: 2px solid var(--text-primary);
    color: var(--text-primary);
    padding: 20px 80px;
    font-size: 3rem;
    font-weight: 900;
    text-decoration: none;
    letter-spacing: 15px;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    clip-path: polygon(20px 0%, 100% 0%, calc(100% - 20px) 100%, 0% 100%);
    overflow: hidden;
    display: flex;
    justify-content: center;
    align-items: center;
    min-width: 400px;
}

.main-enter-btn:hover {
    background: var(--text-primary);
    color: var(--bg-color);
    letter-spacing: 20px;
    box-shadow: 0 0 50px rgba(255, 255, 255, 0.4);
    transform: scale(1.05);
}

.tab-nav {
    display: flex;
    border-bottom: 1px solid var(--border-color);
    padding: 30px 60px;
    gap: 40px;
}

.tab-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-family: inherit;
    font-size: 1rem;
    cursor: pointer;
    letter-spacing: 3px;
    transition: var(--transition-fast);
    position: relative;
}

.tab-btn:hover, .tab-btn.active {
    color: var(--text-primary);
}

.tab-btn.active::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 100%;
    height: 1px;
    background: var(--text-primary);
}

.panel-container {
    flex-grow: 1;
    padding: 60px 80px;
    overflow-y: auto;
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

.section-title {
    font-size: 3rem;
    margin-bottom: 50px;
    letter-spacing: 6px;
    font-weight: 700;
    text-transform: uppercase;
}

.info-card {
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
    padding: 40px;
}

.info-card p {
    font-size: 1.3rem;
    line-height: 2;
    color: var(--text-secondary);
    max-width: 900px;
}

.minimal-table {
    width: 100%;
    border-collapse: collapse;
}

.minimal-table th {
    text-align: left;
    padding: 25px;
    color: var(--text-secondary);
    font-size: 0.9rem;
    border-bottom: 1px solid var(--border-color);
    letter-spacing: 2px;
}

.minimal-table td {
    padding: 25px;
    border-bottom: 1px solid var(--border-color);
    font-size: 1.2rem;
}

.sponsor-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(250px, 1fr));
    gap: 30px;
}

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

.sponsor-card {
    background: var(--glass-bg);
    border: 1px solid var(--border-color);
    height: 120px;
    display: flex;
    justify-content: center;
    align-items: center;
    font-size: 1.1rem;
    letter-spacing: 4px;
    transition: var(--transition-fast);
    text-align: center;
    padding: 20px;
    position: relative;
    overflow: hidden;
}

.sponsor-card:hover {
    border-color: var(--text-primary);
}

.sponsor-card::after {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: conic-gradient(transparent, transparent, transparent, var(--text-primary));
    animation: rotateBorder 4s linear infinite;
    opacity: 0;
    transition: opacity 0.3s;
    pointer-events: none;
}

.sponsor-card:hover::after {
    opacity: 0.15;
}

@keyframes rotateBorder {
    from { transform: rotate(0deg); }
    to { transform: rotate(360deg); }
}

/* Links */
.link-group {
    display: flex;
    flex-direction: column;
    gap: 25px;
}

.minimal-link {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 40px;
    background: var(--glass-bg);
    border: 1px solid var(--border-color);
    text-decoration: none;
    color: var(--text-primary);
    transition: var(--transition-fast);
}

.minimal-link:hover {
    background: rgba(255, 255, 255, 0.05);
    padding-left: 50px;
}

.link-label {
    font-size: 1.8rem;
    letter-spacing: 5px;
}

/* Scrollbar */
::-webkit-scrollbar {
    width: 4px;
}
::-webkit-scrollbar-track {
    background: transparent;
}
::-webkit-scrollbar-thumb {
    background: var(--border-color);
}
::-webkit-scrollbar-thumb:hover {
    background: var(--text-secondary);
}

@media (max-width: 992px) {
    .main-enter-btn {
        font-size: 4rem;
        letter-spacing: 15px;
    }
    .panel-container {
        padding: 40px;
    }
    .section-title {
        font-size: 2rem;
    }
}

/* Certificate */
.header-actions {
    display: flex;
    align-items: center;
    gap: 30px;
}

.home-actions {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 28px;
}

.cert-enter-btn {
    background: transparent;
    border: 2px solid var(--text-secondary);
    color: var(--text-secondary);
    font-family: inherit;
    font-size: 1.4rem;
    font-weight: 700;
    letter-spacing: 10px;
    padding: 14px 70px;
    cursor: pointer;
    clip-path: polygon(20px 0%, 100% 0%, calc(100% - 20px) 100%, 0% 100%);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    display: flex;
    justify-content: center;
    align-items: center;
}

.cert-enter-btn:hover {
    color: var(--bg-color);
    background: var(--text-secondary);
    border-color: var(--text-secondary);
    letter-spacing: 14px;
    box-shadow: 0 0 30px rgba(255, 255, 255, 0.2);
}

#cert-view {
    padding: 0;
    overflow-y: auto;
    display: flex;
}

.cert-inner {
    margin: auto;
    width: 100%;
    max-width: 1000px;
    padding: 60px 40px;
}

.cert-header {
    text-align: center;
}

.cert-sub {
    color: var(--text-secondary);
    letter-spacing: 3px;
    margin-top: -30px;
    margin-bottom: 50px;
    font-size: 0.9rem;
}

.cert-search {
    margin-bottom: 50px;
    max-width: 1000px;
}

.cert-search-row {
    display: flex;
    gap: 20px;
}

.cert-year-list {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-bottom: 20px;
}

.cert-year-btn {
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    font-family: inherit;
    font-size: 0.9rem;
    letter-spacing: 3px;
    padding: 10px 24px;
    cursor: pointer;
    transition: var(--transition-fast);
    position: relative;
}

.cert-year-btn:hover {
    color: var(--text-primary);
    border-color: var(--text-secondary);
}

.cert-year-btn.active {
    color: var(--text-primary);
    border-color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
}

.cert-search input {
    background: var(--glass-bg);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    font-family: inherit;
    font-size: 1rem;
    letter-spacing: 2px;
    padding: 16px 20px;
    outline: none;
    transition: var(--transition-fast);
    flex-grow: 1;
    min-width: 0;
}

.cert-search input:focus {
    border-color: var(--text-primary);
}

.cert-download-btn {
    background: transparent;
    border: 1px solid var(--text-primary);
    color: var(--text-primary);
    font-family: inherit;
    font-size: 1rem;
    letter-spacing: 3px;
    padding: 16px 40px;
    cursor: pointer;
    transition: var(--transition-fast);
}

.cert-download-btn:hover {
    background: var(--text-primary);
    color: var(--bg-color);
}

.cert-notfound {
    border: 1px dashed var(--border-color);
    background: var(--glass-bg);
    padding: 60px;
    text-align: center;
    color: var(--text-secondary);
    letter-spacing: 4px;
    font-size: 1.1rem;
    line-height: 2;
    max-width: 1000px;
}

.cert-notfound span {
    font-size: 0.85rem;
}

@media (max-width: 768px) {
    /* 证书页不需要年份侧栏，窄屏下隐藏以让出宽度 */
    #app-container:has(#cert-view.active) .sidebar {
        display: none;
    }
    .cert-inner {
        padding: 40px 20px;
    }
    .cert-search-row {
        flex-direction: column;
    }
    .cert-year-list {
        justify-content: center;
    }
    .cert-year-btn {
        padding: 8px 16px;
        letter-spacing: 2px;
    }
    .cert-download-btn {
        width: 100%;
    }
    .cert-header .section-title {
        font-size: 1.6rem;
        letter-spacing: 3px;
        margin-bottom: 30px;
    }
    .cert-sub {
        margin-top: -16px;
        margin-bottom: 30px;
        letter-spacing: 2px;
    }
    .cert-notfound {
        padding: 30px 20px;
        font-size: 0.95rem;
        letter-spacing: 2px;
    }
    .cert-enter-btn {
        font-size: 1rem;
        letter-spacing: 4px;
        padding: 12px 24px;
    }
}

@media (max-width: 480px) {
    .global-header {
        padding: 0 16px;
    }
    .header-actions {
        gap: 16px;
    }
    .home-icon-btn {
        font-size: 0.75rem;
        letter-spacing: 2px;
    }
    .brand-title {
        display: none;
    }
}