/**
 * Header Styles
 * 头部和搜索框样式 - 简洁版
 */

/* ==========================================================================
    站点头部
    ========================================================================== */

.header-nav {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 60px;
    background: linear-gradient(90deg, var(--color-primary), var(--color-primary));
    z-index: 9999;
}

.header-container {
    display: grid;
    grid-template-columns: auto 1fr auto;
    grid-template-rows: 1fr;
    gap: 20px;
    align-items: center;
    height: 100%;
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ==========================================================================
    Logo
    ========================================================================== */

.logo {
    grid-column: 1;
    grid-row: 1;
    display: flex;
    align-items: center;
    color: #fff;
    font-size: 26px;
    text-decoration: none;
    z-index: 10;
    height: 100%;
}

.logo img {
    height: 32px;
    vertical-align: middle;
    margin-right: 8px;
}

.logo img:last-child {
    height: 20px;
}

.logo:hover {
    opacity: 0.9;
}

/* ==========================================================================
    搜索框
    ========================================================================== */

.search-box {
    grid-column: 2;
    grid-row: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 10;
    height: 100%;
}

.search-box form {
    position: relative;
    display: flex;
    align-items: center;
    margin: 0;
    padding: 0;
}

.search-input {
    width: 320px;
    max-width: 100%;
    padding: 10px 15px 10px 38px;
    border: none;
    border-radius: 25px;
    background: rgba(255, 255, 255, 0.95);
    font-size: var(--font-size-base);
    transition: all var(--transition-normal);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
}

.search-input:focus {
    width: 360px;
    outline: none;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
    background: #fff;
}

.search-input::placeholder {
    color: #999;
}

.search-icon {
    position: absolute;
    left: 14px;
    width: 16px;
    height: 16px;
    pointer-events: none;
    opacity: 0.5;
}

/* ==========================================================================
    响应式布局
    ========================================================================== */

/* 大屏幕 (>1400px) */
@media (min-width: 1401px) {
    .header-container {
        padding: 12px 40px;
    }
    
    .search-input {
        width: 380px;
    }
    
    .search-input:focus {
        width: 420px;
    }
}

/* 中等屏幕 (992px - 1400px) */
@media (max-width: 1400px) and (min-width: 992px) {
    .header-container {
        grid-template-columns: auto 1fr auto;
        gap: 15px;
    }
    
    .search-input {
        width: 280px;
    }
    
    .search-input:focus {
        width: 320px;
    }
}

/* 平板和移动端 (<=991px) */
@media (max-width: 991px) {
    .header-nav {
        height: 56px;
    }
    
    .header-container {
        grid-template-columns: auto auto;
        grid-template-rows: 1fr;
        padding: 0 15px;
    }
    
    .logo {
        grid-column: 1;
    }
    
    .search-box {
        grid-column: 2;
        justify-content: flex-end;
    }
    
    .search-input {
        width: 200px;
        padding: 8px 12px 8px 32px;
        font-size: var(--font-size-md);
    }
    
    .search-input:focus {
        width: 240px;
    }
}

/* 大屏移动端 (576px - 767px) */
@media (max-width: 767px) {
    .header-container {
        padding: 0 12px;
    }
    
    .logo img:first-child {
        height: 28px;
    }
    
    .search-input {
        width: 140px;
        padding: 7px 10px 7px 28px;
        font-size: var(--font-size-sm);
    }
    
    .search-input:focus {
        width: 180px;
    }
    
    .search-icon {
        left: 10px;
        width: 14px;
        height: 14px;
    }
}

/* 小屏移动端 (<576px) */
@media (max-width: 480px) {
    .header-nav {
        height: 50px;
    }
    
    .header-container {
        padding: 0 10px;
    }
    
    .logo {
        font-size: 18px;
    }
    
    .logo img:first-child {
        height: 22px;
        margin-right: 6px;
    }
    
    .search-input {
        width: 160px;
        padding: 6px 8px 6px 24px;
        font-size: 13px;
    }
    
    .search-input:focus {
        width: 190px;
    }
    
    .search-icon {
        left: 8px;
        width: 12px;
        height: 12px;
    }
}

/* ==========================================================================
    深色模式
    ========================================================================== */

html.dark-mode .header-nav {
    background: linear-gradient(90deg, var(--color-primary-dark), var(--color-primary-dark));
}

html.dark-mode .logo {
    color: #B0B0B0;
}

html.dark-mode .search-input {
    background: var(--color-bg-dark);
    color: var(--color-text);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
}

html.dark-mode .search-input:focus {
    background: var(--color-bg-dark);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
}

/* ==========================================================================
    动画效果
    ========================================================================== */

/* 搜索框焦点动画 */
.search-input {
    animation: pulse 2s infinite;
}

.search-input:focus {
    animation: none;
}

@keyframes pulse {
    0%, 100% {
        box-shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    }
    50% {
        box-shadow: 0 2px 12px rgba(0, 0, 0, 0.15);
    }
}