/* ==========================================================================
   1. GLOBAL VARIABLES & THEMES
   ========================================================================== */
:root {
    --bg-color: #ffffff;
    --text-color: #111111;
    --secondary-text: #666666;
    --card-bg: #f9f9f9;
    --border-color: #e2e2e2;
    --primary-accent: #000000;
    --primary-accent-text: #ffffff;
    --btn-hover: #333333;
    --transition: all 0.3s ease;
}

.dark-mode {
    --bg-color: #121212;
    --text-color: #f1f1f1;
    --secondary-text: #aaaaaa;
    --card-bg: #1e1e1e;
    --border-color: #333333;
    --primary-accent: #ffffff;
    --primary-accent-text: #000000;
    --btn-hover: #cccccc;
}

/* ==========================================================================
   2. RESET & BASE STYLES
   ========================================================================== */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

body {
    background-color: var(--bg-color);
    color: var(--text-color);
    transition: var(--transition);
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* ==========================================================================
   3. HEADER & DESKTOP NAVIGATION
   ========================================================================== */
header {
    width: 100%;
    background: var(--bg-color);
    border-bottom: 1px solid var(--border-color);
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 15px;
    padding-bottom: 15px;
}
 
.logo a { 
    font-size: 24px; 
    font-weight: 800; 
    text-decoration: none; 
    color: var(--text-color); 
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 24px;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
}

.nav-links a:hover {
    color: var(--secondary-text);
}

.theme-toggle {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    color: var(--text-color);
    padding: 8px 16px;
    border-radius: 20px;
    cursor: pointer;
    font-weight: 600;
}

/* --- Desktop Dropdown Menu --- */
.dropdown {
    position: relative;
    display: inline-block;
}

.dropdown p, .dropbtn {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    cursor: pointer;
    margin: 0;
}

.dropdown-content {
    display: none;
    position: absolute;
    background-color: var(--card-bg);
    min-width: 220px;
    box-shadow: 0px 8px 16px rgba(0,0,0,0.1);
    z-index: 1001;
    border-radius: 8px;
    border: 1px solid var(--border-color);
    top: 100%; 
    left: -10px;
}

.dropdown-content a {
    color: var(--text-color);
    padding: 12px 16px;
    text-decoration: none;
    display: block;
    font-size: 14px;
    border-bottom: 1px solid var(--border-color);
}

.dropdown-content a:last-child {
    border-bottom: none;
}

.dropdown-content a:hover {
    background-color: var(--border-color);
}

.dropdown:hover .dropdown-content {
    display: block;
}

/* ==========================================================================
   4. MOBILE NAVIGATION (OFFCANVAS & DROPDOWN)
   ========================================================================== */
.hamburger {
    display: none;
    font-size: 28px;
    cursor: pointer;
    user-select: none;
}

.offcanvas {
    position: fixed;
    top: 0;
    right: -300px;
    width: 280px;
    height: 100vh;
    background: var(--card-bg);
    box-shadow: -5px 0 15px rgba(0,0,0,0.2);
    transition: right 0.3s ease;
    z-index: 2000;
    padding: 20px;
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.offcanvas.open {
    right: 0;
}

.offcanvas-close {
    font-size: 36px;
    cursor: pointer;
    align-self: flex-end;
    line-height: 1;
    user-select: none;
}

.offcanvas a {
    text-decoration: none;
    color: var(--text-color);
    font-weight: 500;
    font-size: 18px;
}

.offcanvas .theme-toggle {
    margin-top: 10px;
}

/* --- Fixed Mobile Dropdown Menu --- */
.mobile-dropdown {
    display: flex;
    flex-direction: column;
    width: 100%;
}

.mobile-dropdown p {
    font-size: 18px;
    font-weight: 500;
    color: var(--text-color);
    cursor: pointer;
    margin: 0;
    padding: 10px 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.mobile-dropdown-content {
    display: none; /* Hidden by default */
    flex-direction: column;
    padding-left: 15px;
    margin-top: 5px;
    border-left: 2px solid var(--border-color);
    gap: 10px;
}

/* This class is toggled by JS */
.mobile-dropdown-content.show {
    display: flex;
}

.mobile-dropdown-content a {
    font-size: 16px;
    padding: 5px 0;
    color: var(--secondary-text);
}

.mobile-dropdown-content a:hover {
    color: var(--text-color);
}

@media (max-width: 900px) {
    .nav-links { display: none; }
    .hamburger { display: block; }
}

/* ==========================================================================
   6. FOOTER & BACK TO TOP
   ========================================================================== */
footer {
    width: 100%;
    background: var(--bg-color);
    padding: 40px 0;
    border-top: 1px solid var(--border-color);
    text-align: center;
    color: var(--secondary-text);
    margin-top: 40px;
}

.footer-links a {
    color: var(--text-color);
    text-decoration: none;
    margin: 0 10px;
}

#backToTop {
    display: none; 
    position: fixed;
    bottom: 20px;
    right: 20px;
    z-index: 99;
    font-size: 20px;
    border: none;
    outline: none;
    background-color: gray; 
    color: white;
    cursor: pointer;
    padding: 0 8px;
    border-radius: 8px;
    transition: transform 0.3s, background-color 0.3s;
}

#backToTop:hover {
    background-color: #c9cbd6;
    transform: translateY(-5px);
}

body.dark-mode #backToTop {
    background-color: #555;
}