:root {
    --primary-color: #2e7d32;
    --primary-dark: #1b5e20;
    --primary-light: #4caf50;
    --sidebar-width: 60px;
    --topbar-height: 3.5rem;
    --text-light: #ffffff;
    --text-dark: #333333;
    --bg-light: #f8f9fa;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Ubuntu-R', Ubuntu, sans-serif;
}

@font-face {
    font-family: 'Ubuntu-R';
    src: url('/static/fonts/Ubuntu-R.ttf') format('truetype');
    font-weight: normal;
    font-style: normal;
    font-display: swap;
}

body {
    color: var(--text-dark);
    overflow-x: hidden;
}

#progress-container {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 3px;
  background-color: transparent;
  z-index: 9999;
  transition: opacity 0.2s ease-out; 
}

#progress-bar {
  width: 0%;
  height: 100%;
  background-color: #90EE90; 
  transition: width 0.2s ease-in-out; 
}

.topbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--topbar-height);
    background-color: var(--primary-dark);
    color: var(--text-light);
    display: flex;
    align-items: center;
    padding: 0 15px;
    z-index: 1000;
    box-shadow: 0 1px 3px rgba(26, 26, 26, .1);
}

.site-logo-link-top {
    display: flex;
    align-items: center;
    margin-right: 15px;
    text-decoration: none;
    transition: filter 0.2s ease;
}

.site-icon-top {
    width: 30px;
    height: 30px;
    transition: filter 0.2s ease;
}

.site-logo-link-top:hover .site-icon-top {
    filter: brightness(0.75);
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    white-space: nowrap;
    color: white;
    text-decoration: none;
    transition: color 0.2s ease;
    cursor: pointer;
    margin-right: 20px;
}

.logo:hover {
    color: #c9c9c9;
}

.breadcrumb {
    flex: 1;
    display: flex;
    align-items: center;
}

.breadcrumb a {
    padding: 0.25em;
    color: rgba(255, 255, 255, 0.8);
    text-decoration: none;
    transition: color 0.2s;
    border-radius: 3px;
    font-size: 1rem;
}

.breadcrumb a:hover {
    background-color: rgb(0 0 0 / 15%);;
}

.breadcrumb en {
    text-align: center;
    font-size: 16px;
    width: 15px;
    color: rgba(255, 255, 255, 0.6);
    font-family: consolas, sans-serif;
}

.auth-buttons {
    display: flex;
    gap: 10px;
}

.auth-btn {
    padding: 8px 16px;
    border-radius: 4px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    border: none;
    font-size: 0.9rem;
}

.login-btn {
    background-color: transparent;
    color: var(--text-light);
    border: 1px solid rgba(255, 255, 255, 0.5);
}

.login-btn:hover {
    background-color: rgba(255, 255, 255, 0.1);
}

.register-btn {
    background-color: var(--text-light);
    color: var(--primary-dark);
}

.register-btn:hover {
    background-color: #f0f0f0;
}

.sidebar {
    position: fixed;
    top: var(--topbar-height);
    left: 0;
    width: var(--sidebar-width);
    height: calc(100vh - var(--topbar-height));
    background-color: var(--text-light);
    transition: width 0.2s ease-out;
    will-change: width;
    overflow-x: hidden;
    overflow-y: auto;
    z-index: 999;
    box-shadow: 2px 0 3px rgba(26, 26, 26, .1);
}

.nav-menu {
    list-style: none;
    padding: 6px 0;
}

.nav-item {
    margin: 2px 0;
}

.nav-link {
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 10px 20px;
    text-decoration: none;
    transition: all 0.2s ease;
    color: var(--text-dark);
    border-left: 3px solid #ffffff00;
    white-space: nowrap;
    overflow: hidden;
    padding-left: 17px;
}

.nav-text {
    font-size: 12px; 
    text-align: center;
    line-height: 1.2;
}

.nav-link:hover {
    background-color: rgba(46, 125, 50, 0.08);
    color: var(--primary-color);
}

.nav-link.active {
    background-color: rgba(46, 125, 50, 0.12);
    color: var(--primary-color);
    border-left: 3px solid var(--primary-color);
}

.nav-icon {
    width: 20px;
    text-align: center;
    font-size: 1.1rem;
    color: inherit;
    flex-shrink: 0;
}

.nav-text {
    font-size: 12px;
    text-align: center;
    line-height: 1.2;
}

.main-content {
    margin-top: var(--topbar-height);
    margin-left: var(--sidebar-width);
    padding: 30px;
    transition: margin-left 0.3s ease;
    min-height: calc(100vh - var(--topbar-height));
    background-image: url(/images/bg.png);
    background-color: #1ea761;
    background-size: 350px;
}

.content-card {
    display: block;
    background-color: #fff;
    border-radius: 4px;
    box-shadow: 0 1px 3px #1a1a1a1a;
    box-sizing: border-box;
    margin-bottom: 1.3em;
    padding: 1.5em;
}

.content-title-h2{
    color: var(--primary-dark);
    margin-bottom: 15px;
    font-size: 1.4rem;
}

.content-title-h1{
    color: var(--primary-dark);
    margin-bottom: 15px;
    font-size: 1.75em;
}

.content-text {
    line-height: 1.6;
    color: #555;
}

.error-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
}

.error-title-section {
    margin-bottom: 30px;
}

.error-tip {
    margin-top: 10px;
    color: #4f4f4f;
}

.error-main-title {
    font-size: 48px;
    font-weight: bold;
    color: black;
    margin-bottom: 10px;
    letter-spacing: 2px;
}

.error-sub-title {
    font-size: 36px;
    font-weight: bold;
    color: black;
    margin-top: 0;
    letter-spacing: 1px;
}

.error-icon-section {
    margin-bottom: 40px;
}

.error-image {
    max-width: 200px;
    width: 100%;
    height: auto;
}

.error-button-section {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.error-btn {
    padding: 10px 30px;
    font-size: 18px;
    font-weight: bold;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    transition: filter 0.1s ease;
    position: relative;
}

.error-btn-primary {
    background-color: #1DD129;
    color: white;
    border: 7px solid #17A921;
}

.error-btn-primary:hover {
    filter: brightness(0.85);
}

.error-btn-secondary {
    background-color: #666666;
    color: white;
    border: 7px solid #535353;
}

.error-btn-secondary:hover {
    filter: brightness(0.85);
}