:root {
    --primary-bg: #121212;
    --secondary-bg: #1e1e1e;
    --accent-primary: #2d76cc;
    --accent-hover: #1d5bb1;
    --accent-secondary: #28a746;
    --text-primary: #ffffff;
    --text-secondary: #b0b0b0;
    --text-muted: #888;
    --border-color: rgba(255, 255, 255, 0.1);
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, 'Open Sans', 'Helvetica Neue', sans-serif;
    --header-height: 80px;
    --border-radius-soft: 10px;
    --border-radius-round: 24px;
    --transition-speed: 0.3s;
}

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

body {
    font-family: var(--font-primary);
    background: var(--primary-bg);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
    padding-top: var(--header-height);
    font-size: 15px;
}

.content {
    flex: 1;
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: var(--container-padding, 20px);
    position: relative;
}

/* HEADER */
header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--header-height);
    background: var(--secondary-bg);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
    z-index: 1000;
    border-bottom: 1px solid var(--border-color);
}

/* HEADER CONTENT */
.header__container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 20px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 20px;
}

/* LOGO LINK */
.logo-link {
    display: flex;
    align-items: center;
    text-decoration: none;
    flex-shrink: 0;
    gap: 12px;
}

.logo-link h1 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    margin: 0;
    transition: color var(--transition-speed) ease;
    white-space: nowrap;
}

.logo-link:hover h1 {
    color: var(--accent-primary);
}

/* MOBILE ACTIONS */
.header__mobile-actions {
    display: none;
    gap: 8px;
    align-items: center;
}

/* SEARCH CONTAINER */
.search-container {
    flex-grow: 1;
    max-width: 500px;
    min-width: 220px;
    margin: 0 20px;
    display: flex;
    align-items: center;
}

.search-wrapper {
    display: flex;
    align-items: center;
    background: var(--primary-bg);
    border-radius: var(--border-radius-soft);
    padding: 0 16px;
    transition: all var(--transition-speed);
    border: 1.5px solid var(--border-color);
    height: 44px;
    width: 100%;
    position: relative;
}

.search-wrapper:hover {
    background: rgba(255, 255, 255, 0.04);
    border-color: rgba(45, 118, 204, 0.5);
}

.search-wrapper:focus-within {
    background: rgba(255, 255, 255, 0.06);
    border-color: var(--accent-primary);
}

#paper-search {
    width: 100%;
    background: transparent;
    border: none;
    outline: none;
    color: var(--text-primary);
    font-size: 1rem;
    padding: 8px 0;
}

#paper-search::placeholder {
    color: var(--text-secondary);
    opacity: 0.85;
}

/* SEARCH DROPDOWN */
.search-dropdown {
    position: absolute;
    top: 100%;
    left: 0;
    right: 0;
    background: var(--secondary-bg);
    border: 1.5px solid var(--accent-primary);
    border-radius: var(--border-radius-soft);
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.3);
    z-index: 3000;
    max-height: 50vh;
    overflow-y: auto;
    display: none;
    margin-top: 6px;
}

.search-result-row {
    display: flex;
    align-items: center;
    padding: 12px 16px;
    cursor: pointer;
    transition: all 0.2s ease;
    background: transparent;
    border-bottom: 1px solid var(--border-color);
    gap: 12px;
}

.search-result-row:last-child {
    border-bottom: none;
}

.search-result-row:hover,
.search-result-row.active {
    background: rgba(45, 118, 204, 0.15);
    border-color: rgba(45, 118, 204, 0.3);
}

.result-subject {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--text-primary);
    flex: 1;
}

.search-result-row:hover .result-subject,
.search-result-row.active .result-subject {
    color: var(--accent-primary);
}

.result-branch {
    font-size: 0.8rem;
    font-weight: 500;
    color: var(--text-secondary);
    background: rgba(45, 118, 204, 0.1);
    padding: 3px 10px;
    border-radius: 10px;
    white-space: nowrap;
    flex-shrink: 0;
}

.search-no-results {
    padding: 24px;
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.95rem;
    font-style: italic;
}

/* MOBILE SEARCH TOGGLE */
.mobile-search-toggle {
    display: none;
    align-items: center;
    justify-content: center;
    background: var(--accent-primary);
    border: 1.5px solid var(--accent-primary);
    border-radius: 50%;
    color: #ffffff;
    cursor: pointer;
    height: 44px;
    width: 44px;
    transition: all 0.2s ease;
}

.mobile-search-toggle:hover {
    background: #1d5bb1;
    border-color: #1d5bb1;
    transform: scale(1.05);
}

.mobile-search-toggle.active {
    background: #28a746;
    border-color: #28a746;
}

.search-icon-svg {
    height: 22px;
    width: 22px;
}

/* MOBILE MENU TOGGLE */
.mobile-menu-toggle {
    display: none;
    background: var(--accent-secondary);
    border: 1.5px solid var(--accent-secondary);
    border-radius: 8px;
    color: #ffffff;
    cursor: pointer;
    padding: 8px;
    z-index: 1001;
    height: 44px;
    width: 44px;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
}

.mobile-menu-toggle:hover {
    background: #1f8736;
    border-color: #1f8736;
    transform: scale(1.05);
}

.menu-icon {
    position: relative;
    width: 24px;
    height: 2px;
    background-color: #ffffff;
    display: block;
    transition: all 0.3s ease;
}

.menu-icon::before,
.menu-icon::after {
    content: '';
    position: absolute;
    width: 24px;
    height: 2px;
    background-color: #ffffff;
    left: 0;
    transition: all 0.3s ease;
}

.menu-icon::before {
    top: -8px;
}

.menu-icon::after {
    top: 8px;
}

.mobile-menu-toggle.active {
    background: #d43b3b;
    border-color: #d43b3b;
}

.mobile-menu-toggle.active .menu-icon {
    background-color: transparent;
}

.mobile-menu-toggle.active .menu-icon::before {
    transform: rotate(45deg);
    top: 0;
}

.mobile-menu-toggle.active .menu-icon::after {
    transform: rotate(-45deg);
    top: 0;
}

/* MOBILE MENU */
.mobile-menu {
    display: none;
    flex-direction: column;
    position: fixed;
    top: 0;
    right: 0;
    width: 85vw;
    max-width: 320px;
    height: 100vh;
    background: var(--secondary-bg);
    box-shadow: -4px 0 24px rgba(0, 0, 0, 0.5);
    z-index: 2000;
    padding: 4rem 1.5rem 2rem 1.5rem;
    transform: translateX(100%);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    border-left: 3px solid var(--accent-primary);
}

.mobile-menu.open {
    display: flex;
    transform: translateX(0);
}

.mobile-menu__close {
    position: absolute;
    top: 0.9rem;
    right: 0.9rem;
    background: rgba(212, 59, 59, 0.12);
    border: 1.5px solid rgba(212, 59, 59, 0.25);
    color: #ffdddd;
    font-size: 22px;
    cursor: pointer;
    width: 44px;
    height: 44px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 10px;
    transition: transform 0.18s ease, background 0.18s ease, color 0.18s ease;
    box-shadow: 0 8px 20px rgba(0,0,0,0.45);
    z-index: 10;
    line-height: 1;
}

.mobile-menu__close:hover,
.mobile-menu__close:focus {
    background: #d43b3b;
    border-color: #d43b3b;
    color: #fff;
    transform: rotate(90deg) scale(1.05);
    outline: none;
}

.mobile-menu a {
    color: var(--text-primary);
    text-decoration: none;
    font-size: 1.05rem;
    font-weight: 500;
    padding: 1rem 1.2rem;
    border-radius: 10px;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    gap: 12px;
    background: rgba(255, 255, 255, 0.04);
    margin-bottom: 8px;
    border: 1px solid transparent;
}

.mobile-menu a:hover {
    background: rgba(45, 118, 204, 0.2);
    transform: translateX(8px);
    color: var(--accent-primary);
    border-color: rgba(45, 118, 204, 0.4);
}

/* HEADER ACTIONS */
.header__actions {
    display: flex;
    align-items: center;
    gap: 12px;
    flex-shrink: 0;
}

/* SPPUCODES BUTTON */
.sppucodes-button {
    padding: 0 16px;
    border-radius: var(--border-radius-soft);
    font-weight: 600;
    font-size: 0.9rem;
    text-decoration: none;
    transition: all var(--transition-speed);
    border: 1.5px solid var(--border-color);
    cursor: pointer;
    white-space: nowrap;
    display: flex;
    align-items: center;
    justify-content: center;
    height: 42px;
    gap: 8px;
    background-color: var(--secondary-bg);
    color: var(--text-primary);
}

.sppucodes-button img {
    width: 24px;
    height: 24px;
    object-fit: contain;
    border-radius: 4px;
}

.sppucodes-button:hover {
    background-color: rgba(255, 255, 255, 0.08);
    border-color: var(--accent-primary);
    transform: translateY(-2px);
}

/* Mobile menu buttons */
.mobile-menu a.sppucodes-button {
    display: flex;
    justify-content: center;
    align-items: center;
    margin-top: 0.5rem;
    padding: 12px 14px;
    border-radius: var(--border-radius-round);
    font-weight: 700;
    font-size: 0.95rem;
    text-transform: uppercase;
    text-decoration: none;
    color: var(--text-primary);
    border: 1.5px solid var(--border-color);
    transition: all var(--transition-speed);
    width: 100%;
    gap: 8px;
    background-color: var(--secondary-bg);
}

.mobile-menu a.sppucodes-button:hover {
    background-color: rgba(255, 255, 255, 0.08);
    border-color: var(--accent-primary);
    transform: translateY(-2px);
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 25px 20px;
    min-height: calc(100vh - var(--header-height));
}

/* BREADCRUMB */
.breadcrumb-container {
    margin-bottom: 30px;
}

.breadcrumb {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 8px;
    padding: 12px 16px;
    background: var(--secondary-bg);
    border-radius: var(--border-radius-soft);
    border: 1px solid var(--border-color);
}

.breadcrumb-item {
    padding: 6px 12px;
    border-radius: 6px;
    font-size: 14px;
    font-weight: 400;
    color: var(--text-secondary);
    transition: all var(--transition-speed) ease;
    display: inline-block;
}

.breadcrumb-item.clickable {
    cursor: pointer;
    background: transparent;
    color: var(--accent-primary);
    border: 1px solid transparent;
}

.breadcrumb-item.clickable:hover {
    background: rgba(45, 118, 204, 0.1);
    border-color: rgba(45, 118, 204, 0.3);
}

.breadcrumb-item.active {
    background: rgba(45, 118, 204, 0.15);
    color: var(--accent-primary);
    font-weight: 600;
    border: 1px solid rgba(45, 118, 204, 0.4);
}

.breadcrumb-separator {
    color: var(--text-muted);
    font-weight: 400;
    margin: 0 2px;
}

/* NAVIGATION */
.navigation {
    flex: 1;
    display: flex;
    flex-direction: column;
}

.nav-level {
    display: none;
    animation: fadeIn 0.4s ease-in-out;
}

.nav-level.active {
    display: block;
}

/* SECTION TITLE */
.section-title {
    color: var(--text-primary);
    font-size: 1.6rem;
    font-weight: 600;
    margin-bottom: 30px;
    padding: 0 16px;
    border-left: 4px solid var(--accent-primary);
    padding-left: 16px;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(15px); }
    to { opacity: 1; transform: translateY(0); }
}

/* CARDS GRID */
.cards-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
    padding: 0;
}

/* CARD STYLES */
.card {
    background: var(--secondary-bg);
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius-soft);
    padding: 25px;
    cursor: pointer;
    transition: all var(--transition-speed) ease;
    display: flex;
    flex-direction: column;
    min-height: 140px;
    position: relative;
    overflow: hidden;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.15);
}

.card::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 3px;
    background: var(--accent-primary);
    transition: width var(--transition-speed) ease-out, left var(--transition-speed) ease-out;
}

.card:hover {
    transform: translateY(-4px);
    border-color: var(--accent-primary);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
}

.card:hover::before {
    width: 100%;
    left: 0;
}

.card-title {
    font-size: 1.4rem;
    font-weight: 600;
    color: var(--text-primary);
    text-align: center;
    line-height: 1.4;
    flex-grow: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 8px 0;
}

/* SUBJECT CARD */
.subject-card {
    min-height: 180px;
    cursor: default;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.subject-card:hover {
    transform: translateY(-4px);
    border-color: var(--accent-primary);
}

.subject-info {
    flex-grow: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding-bottom: 20px;
}

.subject-info h3 {
    color: var(--text-primary);
    margin: 0;
    font-size: 1.3rem;
    font-weight: 600;
    line-height: 1.4;
    text-align: center;
    word-wrap: break-word;
    hyphens: auto;
    overflow-wrap: break-word;
}

/* VIEW BUTTON */
.view-button {
    background: var(--accent-primary);
    color: white;
    border: none;
    padding: 12px 20px;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 500;
    font-size: 14px;
    transition: all var(--transition-speed) ease;
    text-decoration: none;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    text-align: center;
    margin-top: auto;
}

.view-button:hover {
    background: var(--accent-hover);
}

/* LISTS AND CARDS STYLING (Inspired by SPPU Codes index.html) */
.group {
    margin-bottom: 2.5rem;
}

.semester-heading {
    font-size: 1.4rem;
    margin: 2rem 0 1.2rem 0;
    color: #e0e0e0;
    font-weight: 500;
    text-align: left;
    border-left: 4px solid var(--accent-primary);
    padding-left: 12px;
}

.branch-list,
.semester-list,
.subject-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 1.5rem;
    padding: 0;
    margin: 1.5rem 0;
    list-style: none;
}

.branch-list li,
.semester-list li,
.subject-list li {
    animation: fadeIn 0.5s ease forwards;
}

.branch-list a,
.semester-list a,
.subject-list a {
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    gap: 0.75rem;
    background: var(--secondary-bg);
    padding: 2rem;
    border-radius: var(--border-radius-soft);
    text-decoration: none;
    color: var(--text-primary);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
    height: 140px;
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1), box-shadow 0.3s ease, border-color 0.3s ease;
    position: relative;
    overflow: hidden;
    border: 1px solid var(--border-color);
    text-align: center;
}

/* Card Content Styling */
/* Card Content Styling */
.branch-name, 
.full-name, 
.sem-full {
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--text-primary);
    text-align: center;
    line-height: 1.3;
    transition: all 0.3s ease;
    word-wrap: break-word;
    max-width: 90%;
}

.full-name, .sem-full {
    color: #e0e0e0;
    font-weight: 600;
}

/* Hover Effects */
.branch-list a:hover,
.semester-list a:hover,
.subject-list a:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.2);
    border-color: var(--accent-primary);
}

.branch-list a:hover .branch-name,
.semester-list a:hover .sem-full,
.subject-list a:hover .full-name {
    color: var(--accent-primary);
    transform: scale(1.02);
}

/* Bottom Border Hover Animation */
.branch-list a::after,
.semester-list a::after,
.subject-list a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    width: 0;
    height: 3px;
    background-color: var(--accent-primary);
    transition: width 0.3s ease-out, left 0.3s ease-out;
}

.branch-list a:hover::after,
.semester-list a:hover::after,
.subject-list a:hover::after {
    width: 100%;
    left: 0;
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* MOBILE RESPONSIVENESS */
@media (max-width: 899px) {
    :root {
        --header-height: 70px;
    }
    
    body {
        padding-top: var(--header-height);
    }
    
    header {
        height: var(--header-height);
    }
    
    .header__container {
        padding: 0 12px;
    }
    
    .header__mobile-actions {
        display: flex;
    }
    
    .header__actions {
        display: none !important;
    }
    
    .mobile-menu-toggle,
    .mobile-search-toggle {
        display: flex;
    }
    
    /* Mobile Search Bar */
    .search-container {
        position: fixed;
        top: var(--header-height);
        left: 0;
        width: 100vw;
        max-width: 100vw;
        background: var(--secondary-bg);
        z-index: 999;
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: transform 0.3s ease, opacity 0.3s ease, visibility 0.3s ease;
        padding: 14px;
        margin: 0;
        box-shadow: 0 4px 16px rgba(0, 0, 0, 0.3);
        border-bottom: 2px solid var(--accent-primary);
    }
    
    .search-container.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }
    
    .search-wrapper {
        height: 48px;
        padding: 0 14px;
        background: var(--primary-bg);
        border: 2px solid var(--accent-primary);
    }
    
    #paper-search {
        font-size: 1rem;
        padding: 8px 0;
        color: var(--text-primary) !important;
    }
    
    .search-dropdown {
        max-height: 55vh;
        border-radius: 0 0 var(--border-radius-soft) var(--border-radius-soft);
        border-top: none;
        margin-top: 0;
    }
    
    .search-result-row {
        padding: 10px 14px;
    }
    
    .result-subject {
        font-size: 0.9rem;
    }
    
    .result-branch {
        font-size: 0.75rem;
        padding: 2px 8px;
    }
    
    .logo-link h1 {
        font-size: 1.2rem;
    }
    
    .mobile-menu {
        padding: 3.5rem 1.2rem 1.5rem 1.2rem;
    }
    
    .mobile-menu__close {
        top: 0.8rem;
        right: 0.8rem;
        width: 38px;
        height: 38px;
        font-size: 24px;
    }
    
    .container {
        padding: 20px 16px;
    }
    
    .section-title {
        font-size: 1.4rem;
        margin-bottom: 25px;
    }
    
    .cards-grid,
    .branch-list,
    .semester-list,
    .subject-list {
        grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
        gap: 1.2rem;
    }
    
    .card {
        padding: 20px;
        min-height: 120px;
    }
    
    .card-title {
        font-size: 1.2rem;
    }
    
    .subject-card {
        min-height: 160px;
    }
    
    .subject-info h3 {
        font-size: 1.1rem;
    }
    
    .breadcrumb {
        padding: 10px 12px;
    }
    
    .breadcrumb-item {
        padding: 5px 10px;
        font-size: 13px;
    }
}

@media (max-width: 480px) {
    .header__container {
        padding: 0 8px;
    }
    
    .logo-link h1 {
        font-size: 1rem;
    }
    
    .mobile-search-toggle,
    .mobile-menu-toggle {
        width: 40px;
        height: 40px;
    }
    
    .search-container {
        padding: 12px;
    }
    
    .search-wrapper {
        height: 46px;
    }
    
    .container {
        padding: 16px 12px;
    }
    
    .section-title {
        font-size: 1.2rem;
        margin-bottom: 20px;
    }
    
    .cards-grid {
        grid-template-columns: 1fr;
        gap: 14px;
    }
    
    .card {
        padding: 18px;
        min-height: 110px;
    }
    
    .card-title {
        font-size: 1.1rem;
    }
    
    .subject-card {
        min-height: 150px;
    }
    
    .subject-info h3 {
        font-size: 1rem;
    }
    
    .breadcrumb {
        padding: 8px 10px;
        gap: 6px;
    }
    
    .breadcrumb-item {
        padding: 4px 8px;
        font-size: 12px;
    }
    
    .view-button {
        padding: 10px 16px;
        font-size: 13px;
    }
    
    .subject-list,
    .branch-list,
    .semester-list {
        grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
        gap: 1rem;
    }
    
    .subject-list a,
    .branch-list a,
    .semester-list a {
        padding: 1.5rem;
        height: 130px;
        gap: 0.6rem;
    }
    
    .branch-name, .full-name, .sem-full {
        font-size: 1.2rem;
    }
    
    .semester-heading {
        font-size: 1.2rem;
        margin-bottom: 16px;
    }
    
    .mobile-menu {
        width: 90vw;
        padding: 3rem 1rem 1.2rem 1rem;
    }
    
    .mobile-menu__close {
        width: 36px;
        height: 36px;
        font-size: 22px;
        top: 0.7rem;
        right: 0.7rem;
    }
}

/* Tablet Landscape */
@media (min-width: 900px) and (max-width: 1024px) {
    .cards-grid {
        grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    }
    
    .container {
        padding: 25px 30px;
    }
    
    .header__container {
        padding: 0 20px;
    }
    
    .search-container {
        max-width: 350px;
    }
    
    .logo-link h1 {
        font-size: 1.3rem;
    }
}

/* Desktop - Always show search bar */
@media (min-width: 900px) {
    .mobile-search-toggle,
    .mobile-menu-toggle,
    .mobile-menu {
        display: none !important;
    }
    
    .search-container {
        display: flex !important;
        position: static;
        width: auto;
        max-width: 500px;
        margin: 0 20px;
        padding: 0;
        background: none;
        border: none;
        transform: none;
        opacity: 1;
        visibility: visible;
    }
}