body {
    font-family: 'Poppins', sans-serif;
    margin: 0;
    background: linear-gradient(135deg, #d9ecff 0%, #ffe8d6 100%);
    color: #333;
}

/* Header */
.main-header {
    position: sticky;               /* stays at the top */
    top: 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 18px 40px;
    background: rgba(255, 255, 255, 0.4);  /* semi-transparent for glass effect */
    backdrop-filter: blur(10px);           /* frosted glass effect */
    -webkit-backdrop-filter: blur(10px);   /* Safari support */

    border-bottom: 1px solid rgba(255, 255, 255, 0.3); /* subtle border */
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);         /* gentle shadow */
    
    z-index: 100; /* stays above content */
}
.logo { height: 60px; }

.navbar ul {
    display: flex;
    gap: 20px;
    list-style: none;
}

.navbar a {
    text-decoration: none;
    font-weight: 500;
    color: #333;
    transition: color 0.2s ease;
    padding: 6px 12px;
    border-radius: 6px;
}
.navbar a:hover,
.navbar a.active {
    color: #007bff;
    background-color: rgba(0, 119, 255, 0.1);
}

.sign-btn {
    background: #007bff;
    color: white !important;
    padding: 6px 14px;
    border-radius: 6px;
}

/* ================= HAMBURGER - HIDDEN ON DESKTOP ================= */
.hamburger {
    display: none;          /* Hidden on desktop by default */
    background: none;
    border: none;
    font-size: 28px;
    cursor: pointer;
    color: #333;
    margin-left: auto;      /* Push to right when shown */
}


/*============================
   RESPONSIVE NAVIGATION
   ===========================*/
@media (max-width: 700px) {
    .hamburger {
        display: block;      /* show hamburger */
        margin-left: auto;   /* push to right */
        font-size: 28px;
        cursor: pointer;
    }

    .navbar ul {
        display: none;       /* hide menu initially */
        flex-direction: column;
        gap: 10px;
        position: absolute;
        top: 100%;           /* dropdown below header */
        right: 0;            /* align to right */
        background: rgba(255, 255, 255, 0.7); /* glass effect */
        backdrop-filter: blur(10px);
        -webkit-backdrop-filter: blur(10px);
        padding: 10px 20px;
        border-radius: 0 0 12px 12px;
        z-index: 99;
    }

    .navbar ul.show {
        display: flex;       /* show menu when toggled */
    }

    .main-header {
        flex-direction: row;  /* logo left, hamburger right */
        align-items: center;
        padding: 15px 20px;
    }
}

/* ===== STUDY SKILLS PAGE - PROFESSIONAL DESIGN ===== */

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

body {
    font-family: 'Poppins', sans-serif;
    margin: 0;
    background: linear-gradient(135deg, #f8fbff 0%, #fff9f5 100%);
    color: #333;
    line-height: 1.6;
}

/* Header - Professional Glass Effect */
.main-header {
    position: sticky;
    top: 0;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 18px 40px;
    background: rgba(255, 255, 255, 0.81);/* semi-transparent for glass effect */
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(0, 119, 255, 0.1);
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.08);
    z-index: 1000;
}

.logo {
    height: 50px;
    transition: transform 0.3s ease;
}

.logo:hover {
    transform: scale(1.05);
}

.navbar ul {
    display: flex;
    gap: 25px;
    list-style: none;
    align-items: center;
}

.navbar a {
    text-decoration: none;
    font-weight: 500;
    color: #333;
    transition: all 0.3s ease;
    padding: 8px 16px;
    border-radius: 8px;
    font-size: 0.95rem;
    position: relative;
}

.navbar a:not(.sign-btn):hover {
    color: #007bff;
    background: rgba(0, 123, 255, 0.05);
}

.navbar a.active {
    color: #007bff;
    font-weight: 600;
}

.navbar a.active:after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 16px;
    right: 16px;
    height: 3px;
    background: linear-gradient(90deg, #007bff, #00b4ff);
    border-radius: 2px;
}

.sign-btn {
    background: linear-gradient(135deg, #007bff, #0056b3);
    color: white !important;
    padding: 10px 22px;
    border-radius: 8px;
    font-weight: 600;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0, 123, 255, 0.2);
}

.sign-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 123, 255, 0.3);
    background: linear-gradient(135deg, #0056b3, #007bff);
}

.hamburger {
    display: none;
    background: none;
    border: none;
    font-size: 28px;
    cursor: pointer;
    color: #333;
}

/* Hero Section */
.hero-section {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    padding: 80px 40px;
    max-width: 1400px;
    margin: 0 auto;
    align-items: center;
}

.hero-content h1 {
    font-size: 3.2rem;
    color: #003366;
    margin-bottom: 20px;
    line-height: 1.2;
    font-weight: 700;
}

.subtitle {
    font-size: 1.2rem;
    color: #555;
    margin-bottom: 40px;
    line-height: 1.7;
}

.hero-stats {
    display: flex;
    gap: 40px;
    margin-top: 30px;
}

.stat {
    text-align: center;
}

.number {
    display: block;
    font-size: 2.5rem;
    font-weight: 700;
    color: #007bff;
    line-height: 1;
}

.label {
    display: block;
    font-size: 0.9rem;
    color: #666;
    margin-top: 8px;
    font-weight: 500;
}

.hero-image {
    border-radius: 20px;
    overflow: hidden;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.1);
}

.hero-image img {
    width: 100%;
    height: auto;
    display: block;
    transition: transform 0.5s ease;
}

.hero-image:hover img {
    transform: scale(1.03);
}

/* Methods Section */
.methods-section {
    padding: 80px 40px;
    max-width: 1400px;
    margin: 0 auto;
}

.section-header {
    text-align: center;
    margin-bottom: 60px;
}

.section-header h2 {
    font-size: 2.5rem;
    color: #003366;
    margin-bottom: 15px;
    font-weight: 700;
}

.section-header p {
    color: #666;
    font-size: 1.1rem;
    max-width: 700px;
    margin: 0 auto;
}

/* Methods Grid */
.methods-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(380px, 1fr));
    gap: 30px;
}

.method-card {
    background: white;
    border-radius: 20px;
    padding: 30px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.08);
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    border: 1px solid rgba(0, 0, 0, 0.05);
    position: relative;
    overflow: hidden;
}

.method-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.12);
    border-color: rgba(0, 123, 255, 0.2);
}

.card-header {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-bottom: 20px;
}

.card-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, #007bff, #00b4ff);
    border-radius: 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 24px;
    flex-shrink: 0;
}

.card-header h3 {
    font-size: 1.4rem;
    color: #003366;
    font-weight: 600;
    flex-grow: 1;
}

.difficulty {
    padding: 6px 12px;
    background: rgba(0, 123, 255, 0.1);
    color: #007bff;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
}

.card-description {
    color: #555;
    margin-bottom: 25px;
    line-height: 1.7;
}

.card-details {
    display: flex;
    gap: 20px;
    margin-bottom: 25px;
    padding: 15px;
    background: #f8fafc;
    border-radius: 12px;
}

.detail-item {
    display: flex;
    align-items: center;
    gap: 8px;
    color: #666;
    font-size: 0.9rem;
}

.detail-item i {
    color: #007bff;
}

/* Toggle Button */
.toggle-btn {
    width: 100%;
    padding: 15px;
    background: linear-gradient(135deg, #007bff, #0056b3);
    color: white;
    border: none;
    border-radius: 12px;
    font-weight: 600;
    font-size: 1rem;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 15px;
}

.toggle-btn:hover {
    background: linear-gradient(135deg, #0056b3, #003d82);
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0, 123, 255, 0.3);
}

/* Content (Initially Hidden) */
.content {
    display: none;
    padding-top: 25px;
    margin-top: 25px;
    border-top: 2px solid #f0f0f0;
    animation: fadeIn 0.5s ease;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-10px); }
    to { opacity: 1; transform: translateY(0); }
}

.content h4 {
    color: #003366;
    margin-bottom: 20px;
    font-size: 1.2rem;
}

.content ol, .content ul {
    padding-left: 20px;
    margin-bottom: 25px;
}

.content li {
    margin-bottom: 10px;
    color: #555;
    line-height: 1.6;
}

.content li strong {
    color: #003366;
}

/* Special Content Styles */
.pro-tip, .research-note {
    background: #fff8e1;
    padding: 20px;
    border-radius: 12px;
    margin-top: 20px;
    border-left: 4px solid #ffc107;
    display: flex;
    gap: 15px;
    align-items: flex-start;
}

.pro-tip i, .research-note i {
    color: #ffc107;
    font-size: 1.2rem;
    flex-shrink: 0;
    margin-top: 3px;
}

.schedule-grid, .pomodoro-cycle, .cornell-structure, .dual-coding-example {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 15px;
    margin: 25px 0;
}

.schedule-item, .phase, .structure-section, .coding-method {
    background: #f8fafc;
    padding: 20px;
    border-radius: 12px;
    text-align: center;
}

.day, .phase-title, .section-header, .coding-method h5 {
    display: block;
    font-weight: 600;
    color: #007bff;
    margin-bottom: 8px;
}

.task, .phase-duration, .phase-desc {
    display: block;
    color: #666;
    font-size: 0.9rem;
}

.tools, .benefits, .workflow, .tips {
    background: #f0f8ff;
    padding: 20px;
    border-radius: 12px;
    margin-top: 20px;
}

.tools h5, .benefits h5, .workflow h5, .tips h5 {
    color: #007bff;
    margin-bottom: 15px;
}

/* Study Plan CTA */
.study-plan-cta {
    background: linear-gradient(135deg, #003366, #0056b3);
    color: white;
    padding: 80px 40px;
    text-align: center;
    border-radius: 30px;
    margin: 60px auto;
    max-width: 1200px;
    position: relative;
    overflow: hidden;
}

.study-plan-cta:before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100" preserveAspectRatio="none"><path fill="rgba(255,255,255,0.05)" d="M0,0 L100,0 L100,100 L0,100 Z"/></svg>');
    background-size: cover;
}

.cta-content {
    position: relative;
    z-index: 1;
}

.cta-content h2 {
    font-size: 2.5rem;
    margin-bottom: 20px;
    font-weight: 700;
}

.cta-content p {
    font-size: 1.2rem;
    opacity: 0.9;
    margin-bottom: 40px;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.cta-buttons {
    display: flex;
    gap: 20px;
    justify-content: center;
    flex-wrap: wrap;
}

.primary-btn, .secondary-btn {
    padding: 18px 35px;
    border-radius: 12px;
    text-decoration: none;
    font-weight: 600;
    font-size: 1.1rem;
    display: inline-flex;
    align-items: center;
    gap: 12px;
    transition: all 0.3s ease;
}

.primary-btn {
    background: white;
    color: #007bff;
}

.primary-btn:hover {
    background: #f8f9fa;
    transform: translateY(-3px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
}

.secondary-btn {
    background: transparent;
    border: 2px solid white;
    color: white;
}

.secondary-btn:hover {
    background: white;
    color: #007bff;
    transform: translateY(-3px);
}

/* Footer */
footer {
    background: #001f4d;
   color: white;
    padding: 60px 40px 30px;
}

.footer-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 50px;
    max-width: 1400px;
    margin: 0 auto;
}

.footer-left img {
    height: 50px;
    margin-bottom: 20px;
}

.footer-left p {
    color: #b3b3cc;
    margin-bottom: 10px;
}

.footer-tagline {
    font-size: 0.9rem;
    opacity: 0.7;
}

.footer-middle h4, .footer-right h4 {
    color: white;
    margin-bottom: 25px;
    font-size: 1.2rem;
}

.footer-links {
    display: flex;
    flex-direction: column;
    gap: 15px;
}

.footer-links a {
    color: #b3b3cc;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-links a:hover {
    color: white;
    padding-left: 5px;
}

.footer-contact p {
    color: #b3b3cc;
    margin-bottom: 15px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.footer-social {
    display: flex;
    gap: 20px;
    margin-top: 25px;
}

.footer-social a {
    color: #b3b3cc;
    font-size: 1.2rem;
    transition: color 0.3s ease;
}

.footer-social a:hover {
    color: white;
}

.footer-bottom {
    text-align: center;
    margin-top: 50px;
    padding-top: 30px;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    color: #666;
    font-size: 0.9rem;
}

/* ===== RESPONSIVE DESIGN ===== */
@media (max-width: 1024px) {
    .hero-section {
        grid-template-columns: 1fr;
        text-align: center;
        gap: 40px;
    }
    
    .hero-stats {
        justify-content: center;
    }
    
    .methods-grid {
        grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    }
}

@media (max-width: 768px) {
    .main-header {
        padding: 15px 20px;
    }
    
    .hamburger {
        display: block;
    }
    
    .navbar ul {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 20px;
        box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
        border-radius: 0 0 20px 20px;
        z-index: 999;
    }
    
    .navbar ul.show {
        display: flex;
    }
    
    .hero-section {
        padding: 60px 20px;
    }
    
    .hero-content h1 {
        font-size: 2.2rem;
    }
    
    .methods-section {
        padding: 60px 20px;
    }
    
    .methods-grid {
        grid-template-columns: 1fr;
    }
    
    .study-plan-cta {
        padding: 60px 20px;
        margin: 40px 20px;
        border-radius: 20px;
    }
    
    .cta-content h2 {
        font-size: 2rem;
    }
    
    .cta-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .primary-btn, .secondary-btn {
        width: 100%;
        max-width: 300px;
        justify-content: center;
    }
    
    footer {
        padding: 40px 20px;
    }
    
    .footer-container {
        grid-template-columns: 1fr;
        gap: 40px;
        text-align: center;
    }
    
    .footer-contact p {
        justify-content: center;
    }
    
    .footer-social {
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .hero-content h1 {
        font-size: 1.8rem;
    }
    
    .hero-stats {
        flex-direction: column;
        gap: 25px;
    }
    
    .method-card {
        padding: 25px;
    }
    
    .card-header {
        flex-wrap: wrap;
    }
    
    .toggle-btn span {
        font-size: 0.9rem;
    }
}