/* 
 * Navbar Responsive Design
 * 导航栏响应式优化 - 解决上下间距过宽问题
 */

/* ===== CSS Variables ===== */
:root {
    /* Navbar Height Variables for different breakpoints */
    --navbar-height-mobile: 56px;
    --navbar-height-tablet: 60px;
    --navbar-height-desktop: 70px;
    --navbar-height-large: 80px;
    
    /* Navbar Padding Variables */
    --navbar-padding-y-mobile: 0.5rem;
    /* 8px */
    --navbar-padding-y-tablet: 0.75rem;
    /* 12px */
    --navbar-padding-y-desktop: 1rem;
    /* 16px */
    --navbar-padding-y-large: 1.25rem;
    /* 20px */
    
    /* Navbar Item Spacing */
    --navbar-item-padding-mobile: 0.5rem 0.75rem;
    --navbar-item-padding-tablet: 0.5rem 1rem;
    --navbar-item-padding-desktop: 0.75rem 1rem;
    
    /* Dropdown Menu */
    --dropdown-padding-y: 0.5rem;
    --dropdown-item-padding: 0.5rem 1rem;

    /* Navbar Typography */
    --navbar-font-size: 1.375rem; /* 22px */
    --navbar-font-size-mobile: 1.375rem; /* 22px */
}

/* ===== Base Navbar Styles ===== */
.navbar {
    padding-top: var(--navbar-padding-y-mobile);
    padding-bottom: var(--navbar-padding-y-mobile);
    transition: padding 0.3s ease;
}

/* Navbar Brand */
.navbar-brand {
    padding-top: 0.3125rem;
    padding-bottom: 0.3125rem;
    font-size: 1.25rem;
    line-height: inherit;
    white-space: nowrap;
}

/* Navbar Navigation */
.navbar-nav {
    display: flex;
    flex-direction: column;
    padding-left: 0;
    margin-bottom: 0;
    list-style: none;
}

.navbar-nav .nav-link {
    padding: var(--navbar-item-padding-mobile);
    font-size: var(--navbar-font-size);
    line-height: 1.4;
    transition: all 0.3s ease;
}


/* Dropdown Menu Optimization */
.dropdown-menu {
    padding: var(--dropdown-padding-y) 0;
    margin: 0;
    font-size: 1.05rem;
}

.dropdown-item {
    padding: var(--dropdown-item-padding);
    clear: both;
    font-weight: 400;
    color: #212529;
    text-align: inherit;
    white-space: nowrap;
    background-color: transparent;
    border: 0;
    transition: background-color 0.15s ease-in-out;
}

.dropdown-item:hover,
.dropdown-item:focus {
    background-color: #f8f9fa;
}

/* Dropdown Submenu */
.dropdown-submenu {
    position: relative;
}

.dropdown-submenu > .dropdown-menu {
    top: 0;
    left: 100%;
    margin-top: -0.375rem;
    margin-left: -1px;
}

.dropdown-submenu:hover > .dropdown-menu {
    display: block;
}

/* ===== Mobile Portrait (< 576px) ===== */
@media (max-width: 575.98px) {
    :root {
        --navbar-padding-y-mobile: 0.375rem;
        /* 减少到 6px */
    }
    
    .navbar {
        padding-top: var(--navbar-padding-y-mobile);
        padding-bottom: var(--navbar-padding-y-mobile);
        min-height: var(--navbar-height-mobile);
    }
    
    .navbar-brand {
        font-size: 1.1rem;
        padding-top: 0.25rem;
        padding-bottom: 0.25rem;
    }
    
    .navbar-nav .nav-link {
        padding: 0.5rem 0.75rem;
        font-size: var(--navbar-font-size-mobile);
    }
    
    .navbar-toggler {
        padding: 0.25rem 0.5rem;
        font-size: 1rem;
    }
    
    /* Collapsed menu */
    .navbar-collapse {
        padding-top: 0.5rem;
        padding-bottom: 0.5rem;
    }
    
    .dropdown-menu {
        padding: 0.25rem 0;
    }
    
    .dropdown-item {
        padding: 0.5rem 1rem;
        font-size: 1rem;
    }
}

/* ===== Mobile Landscape / Small Tablet (576px - 767.98px) ===== */
@media (min-width: 576px) and (max-width: 767.98px) {
    .navbar {
        padding-top: var(--navbar-padding-y-mobile);
        padding-bottom: var(--navbar-padding-y-mobile);
        min-height: var(--navbar-height-mobile);
    }
    
    .navbar-nav .nav-link {
        padding: 0.5rem 0.875rem;
        font-size: var(--navbar-font-size-mobile);
    }
}

/* ===== Tablet Portrait (768px - 991.98px) ===== */
@media (min-width: 768px) and (max-width: 991.98px) {
    .navbar {
        padding-top: var(--navbar-padding-y-tablet);
        padding-bottom: var(--navbar-padding-y-tablet);
        min-height: var(--navbar-height-tablet);
    }
    
    .navbar-nav .nav-link {
        padding: var(--navbar-item-padding-tablet);
    }
    
    .navbar-brand {
        font-size: 1.2rem;
    }
    
    /* 如果在這個尺寸下導航欄過高，可以減少間距 */
    .navbar-collapse {
        max-height: 60px;
    }
}

/* ===== Desktop Small (992px - 1199.98px) ===== */
@media (min-width: 992px) and (max-width: 1199.98px) {
    .navbar {
        padding-top: var(--navbar-padding-y-tablet);
        padding-bottom: var(--navbar-padding-y-tablet);
        min-height: var(--navbar-height-tablet);
    }
    
    .navbar-nav .nav-link {
        padding: 0.625rem 1rem;
    }
    
    /* 這個尺寸通常是問題區域 - 調整間距 */
    .navbar {
        padding-top: 0.625rem;
        /* 10px */
        padding-bottom: 0.625rem;
        /* 10px */
    }
}

/* ===== Desktop Medium (1200px - 1399.98px) ===== */
@media (min-width: 1200px) and (max-width: 1399.98px) {
    .navbar {
        padding-top: 0.75rem;
        /* 12px */
        padding-bottom: 0.75rem;
        /* 12px */
        min-height: var(--navbar-height-desktop);
    }
    
    .navbar-nav .nav-link {
        padding: var(--navbar-item-padding-desktop);
    }
    
    .navbar-brand {
        font-size: 1.25rem;
    }
    
    /* 確保這個尺寸下不會過高 */
    .navbar-collapse {
        max-height: 70px;
    }
}

/* ===== Desktop Large (1400px - 1919.98px) ===== */
@media (min-width: 1400px) and (max-width: 1919.98px) {
    .navbar {
        padding-top: 0.875rem;
        /* 14px */
        padding-bottom: 0.875rem;
        /* 14px */
        min-height: var(--navbar-height-desktop);
    }
    
    .navbar-nav .nav-link {
        padding: 0.75rem 1.125rem;
    }
}

/* ===== Ultra-Wide Desktop (1920px - 2559.98px) ===== */
@media (min-width: 1920px) and (max-width: 2559.98px) {
    .navbar {
        padding-top: 1rem;
        /* 16px */
        padding-bottom: 1rem;
        /* 16px */
        min-height: var(--navbar-height-desktop);
    }
    
    .navbar-nav .nav-link {
        padding: 0.75rem 1.25rem;
    }
    
    .navbar-brand {
        font-size: 1.375rem;
    }
}

/* ===== 4K/Ultra-Wide (>= 2560px) ===== */
@media (min-width: 2560px) {
    .navbar {
        padding-top: 1rem;
        /* 16px - 不再增加 */
        padding-bottom: 1rem;
        /* 16px - 不再增加 */
        min-height: var(--navbar-height-large);
        max-height: 90px;
        /* 限制最大高度 */
    }
    
    .navbar-nav .nav-link {
        padding: 0.75rem 1.5rem;
    }
    
    .navbar-brand {
        font-size: 1.5rem;
    }
    
    /* 限制容器寬度，避免內容過度分散 */
    .navbar > .container,
    .navbar > .container-fluid {
        max-width: 2400px;
        margin: 0 auto;
    }
}

/* ===== Special Case: 1333px (mentioned in screenshots) ===== */
@media (min-width: 1333px) and (max-width: 1400px) {
    .navbar {
        padding-top: 0.75rem;
        /* 12px */
        padding-bottom: 0.75rem;
        /* 12px */
    }
    
    .navbar-nav .nav-link {
        padding: 0.625rem 1rem;
    }
}

/* ===== Compact Mode Class (optional) ===== */
.navbar-compact {
    padding-top: 0.5rem !important;
    padding-bottom: 0.5rem !important;
    min-height: 50px !important;
}

.navbar-compact .navbar-brand {
    font-size: 1.1rem;
}

.navbar-compact .navbar-nav .nav-link {
    padding: 0.5rem 0.875rem;
}

/* ===== Scrolled State ===== */
.navbar.navbar-scrolled {
    padding-top: 0.5rem;
    padding-bottom: 0.5rem;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

/* ===== Accessibility & Focus States ===== */
.navbar-nav .nav-link:focus,
.dropdown-item:focus {
    outline: 2px solid #0d6efd;
    outline-offset: 2px;
}

/* ===== Animation ===== */
@media (prefers-reduced-motion: reduce) {
    .navbar,
    .navbar-nav .nav-link,
    .dropdown-item {
        transition: none;
    }
}

/* ===== Height Limiting for Specific Problematic Ranges ===== */
/* 如果在 768px - 1200px 之間發現上下間距過大 */
@media (min-width: 768px) and (max-width: 1200px) {
    /* 強制限制導航欄的最大上下內邊距 */
    .navbar {
        padding-top: clamp(0.5rem, 1vw, 0.75rem);
        padding-bottom: clamp(0.5rem, 1vw, 0.75rem);
    }
    
    /* 限制導航項目的上下內邊距 */
    .navbar-nav .nav-link {
        padding-top: 0.5rem;
        padding-bottom: 0.5rem;
    }
    
    /* 下拉選單的垂直間距也要控制 */
    .dropdown-menu {
        padding-top: 0.375rem;
        padding-bottom: 0.375rem;
    }
    
    .dropdown-item {
        padding-top: 0.375rem;
        padding-bottom: 0.375rem;
    }
}

/* ===== Print Styles ===== */
@media print {
    .navbar {
        padding: 0.5rem 0;
        min-height: auto;
    }
    
    .navbar-toggler,
    .dropdown-menu {
        display: none;
    }
}