body {
    font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
    margin: 0;
    padding: 0;
    background: linear-gradient(135deg, #f5f7fa, #e4edf5);
    min-height: 100vh;
    position: relative;
    overflow-x: hidden;
    color: #333;
    transition: background-color 0.3s, color 0.3s;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    padding: 20px 15px;
    position: relative;
    z-index: 1;
}

header {
    text-align: center;
    margin-bottom: 30px;
    color: #2c3e50;
    text-shadow: 0 1px 2px rgba(0,0,0,0.1);
}

.header-top {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 10px;
}

h1 {
    font-size: 2.2rem;
    margin-bottom: 0;
    color: #2c3e50;
}

h2 {
    font-size: 1.5rem;
    margin: 20px 0 15px 0;
    color: #3498db;
}

h3 {
    font-size: 1.3rem;
    margin: 15px 0 10px 0;
    color: #2c3e50;
}

.subtitle {
    font-size: 1.1rem;
    opacity: 0.9;
    color: #7f8c8d;
}

.announcement-bar {
    background: #fff9c4;
    color: #333;
    padding: 12px 15px;
    border-radius: 8px;
    margin-bottom: 20px;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    text-align: center;
    font-weight: 500;
    border-left: 4px solid #ffc107;
}

.category-filter {
    display: flex;
    justify-content: center;
    margin-bottom: 20px;
    gap: 8px;
    flex-wrap: wrap;
}

.category-btn {
    padding: 8px 16px;
    background: rgba(255, 255, 255, 0.9);
    border: none;
    border-radius: 30px;
    font-size: 0.9rem;
    font-weight: bold;
    cursor: pointer;
    transition: all 0.3s ease;
    color: #3498db;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    white-space: nowrap;
}

.category-btn:hover {
    background: rgba(255, 255, 255, 1);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.15);
}

.category-btn.active {
    background: #3498db;
    color: white;
}

.card {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 25px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.05);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
    position: relative;
    overflow: hidden;
}

.card:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.1);
}

.slider-container {
    position: relative;
    width: 100%;
    overflow: hidden;
}

.slider {
    display: flex;
    transition: transform 0.5s ease;
    width: 100%;
}

.slide {
    min-width: 100%;
    width: 100%;
    padding: 15px;
    box-sizing: border-box;
}

.section-header {
    display: flex;
    align-items: center;
    margin-bottom: 15px;
    padding-bottom: 10px;
    border-bottom: 1px solid #eee;
}

.section-number {
    background: #3498db;
    color: white;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    font-size: 1rem;
    margin-right: 12px;
    flex-shrink: 0;
}

.section-title-text {
    font-weight: bold;
    color: #2c3e50;
    font-size: 1.4rem;
}

.recommendation {
    background: #e74c3c;
    color: white;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: bold;
    margin-left: 12px;
    display: inline-block;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.content {
    font-size: 1.2rem;
    line-height: 1.6;
    color: #555;
    margin-bottom: 20px;
    text-align: center;
    font-weight: 500;
}

.highlight {
    color: #e74c3c;
    font-weight: bold;
}

.btn {
    display: inline-block;
    padding: 12px 24px;
    background: linear-gradient(to right, #3498db, #2980b9);
    color: white;
    text-decoration: none;
    border-radius: 50px;
    cursor: pointer;
    border: none;
    font-size: 1rem;
    font-weight: bold;
    margin: 5px;
    box-shadow: 0 3px 10px rgba(52, 152, 219, 0.3);
    transition: all 0.3s ease;
    width: auto;
    min-width: 120px;
    text-align: center;
    position: relative;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(52, 152, 219, 0.4);
    background: linear-gradient(to right, #2980b9, #1c6ea4);
}

.btn:active {
    transform: translateY(1px);
}

.recommended-btn .recommendation {
    position: absolute;
    top: -8px;
    right: -5px;
    font-size: 0.6em;
    padding: 3px 8px;
    border-radius: 10px;
}

.qrcode-container {
    text-align: center;
}

.qrcode-image {
    max-width: 250px;
    width: 100%;
    height: auto;
    margin: 20px auto;
    border: 5px solid white;
    border-radius: 10px;
    box-shadow: 0 5px 15px rgba(0,0,0,0.1);
    display: block;
    opacity: 0;
    transition: opacity 0.3s ease-in;
}

.instructions {
    background: rgba(248, 249, 250, 0.9);
    padding: 20px;
    border-radius: 12px;
    margin-top: 25px;
}

.instructions .section-title {
    font-weight: bold;
    color: #2c3e50;
    font-size: 1.4rem;
    margin-top: 0;
    margin-bottom: 15px;
    text-align: center;
}

.instructions ul {
    padding-left: 20px;
}

.instructions li {
    margin-bottom: 12px;
    line-height: 1.6;
    font-size: 1rem;
}

footer {
    text-align: center;
    color: #7f8c8d;
    margin-top: 30px;
    font-size: 0.9rem;
}

/* Slider navigation */
.slider-nav {
    display: flex;
    justify-content: center;
    margin-top: 15px;
    gap: 8px;
}

.nav-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background-color: #bdc3c7;
    cursor: pointer;
    transition: background-color 0.3s;
}

.nav-dot.active {
    background-color: #3498db;
}

.nav-arrow {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background: rgba(52, 152, 219, 0.7);
    color: white;
    border: none;
    width: 35px;
    height: 35px;
    border-radius: 50%;
    font-size: 1rem;
    cursor: pointer;
    z-index: 10;
}

.nav-arrow.left {
    left: 10px;
}

.nav-arrow.right {
    right: 10px;
}

/* Dark mode toggle button */
.dark-mode-toggle {
    background: rgba(255, 255, 255, 0.2);
    border: none;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.2rem;
    transition: all 0.3s ease;
    box-shadow: 0 2px 5px rgba(0,0,0,0.2);
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1000;
}

.dark-mode-toggle:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: scale(1.1);
}

.moon-icon {
    display: none;
}

/* Dark mode styles */
body.dark-mode {
    background: linear-gradient(135deg, #1a1a2e, #16213e);
    color: #eee;
}

body.dark-mode .header-top h1,
body.dark-mode .section-title-text,
body.dark-mode .content,
body.dark-mode h3 {
    color: #eee;
}

body.dark-mode h2 {
    color: #64b5f6;
}

body.dark-mode .subtitle {
    color: #bbb;
}

body.dark-mode .card {
    background: rgba(30, 30, 46, 0.9);
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.3);
}

body.dark-mode .card:hover {
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.5);
}

body.dark-mode .category-btn {
    background: rgba(50, 50, 70, 0.9);
    color: #64b5f6;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.3);
}

body.dark-mode .category-btn:hover {
    background: rgba(60, 60, 90, 1);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.4);
}

body.dark-mode .category-btn.active {
    background: #64b5f6;
    color: #1a1a2e;
}

body.dark-mode .instructions {
    background: rgba(40, 40, 60, 0.9);
}

body.dark-mode .section-header {
    border-bottom: 1px solid #444;
}

body.dark-mode .section-number {
    background: #64b5f6;
    color: #1a1a2e;
}

body.dark-mode .recommendation {
    background: #ef5350;
}

body.dark-mode .btn {
    box-shadow: 0 3px 10px rgba(33, 150, 243, 0.4);
}

body.dark-mode .btn:hover {
    box-shadow: 0 5px 15px rgba(33, 150, 243, 0.6);
}

body.dark-mode .announcement-bar {
    background: #33334d;
    color: #ddd;
    border-left: 4px solid #ffca28;
}

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

body.dark-mode .nav-dot.active {
    background-color: #64b5f6;
}

body.dark-mode .nav-arrow {
    background: rgba(33, 150, 243, 0.7);
}

body.dark-mode footer {
    color: #aaa;
}

body.dark-mode .dark-mode-toggle {
    background: rgba(50, 50, 70, 0.5);
}

body.dark-mode .dark-mode-toggle:hover {
    background: rgba(60, 60, 90, 0.7);
}

body.dark-mode .sun-icon {
    display: none;
}

body.dark-mode .moon-icon {
    display: inline;
}

@media (max-width: 768px) {
    .container {
        padding: 15px 10px;
    }
    
    .card {
        padding: 15px;
    }
    
    h1 {
        font-size: 1.8rem;
    }
    
    .section-header {
        flex-wrap: wrap;
    }
    
    .section-title-text {
        font-size: 1.2rem;
        margin-bottom: 8px;
    }
    
    .recommendation {
        margin-left: 8px;
        align-self: flex-start;
        font-size: 0.7rem;
        padding: 3px 10px;
    }
    
    .btn {
        width: 100%;
        padding: 14px;
        margin: 8px 0;
        font-size: 1rem;
    }
    
    .content {
        font-size: 1.1rem;
        line-height: 1.5;
    }
    
    .recommended-btn .recommendation {
        top: -10px;
        right: 10px;
        font-size: 0.7em;
    }
    
    .category-filter {
        flex-wrap: wrap;
    }
    
    .category-btn {
        padding: 6px 12px;
        font-size: 1.0rem;
    }
    
    .qrcode-image {
        max-width: 200px;
    }
    
    .header-top {
        flex-direction: column;
        gap: 10px;
    }
    
    .dark-mode-toggle {
        position: fixed;
        top: 15px;
        right: 15px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 10px 8px;
    }
    
    .card {
        padding: 12px;
    }
    
    h1 {
        font-size: 1.6rem;
    }
    
    .section-number {
        width: 40px;
        height: 40px;
        font-size: 1.3rem;
    }
    
    .section-title-text {
        font-size: 1.4rem;
    }
    
    .content {
        font-size: 1.2rem;
        line-height: 1.4;
    }
    
    .btn {
        padding: 12px;
        font-size: 1.1rem;
    }
    
    .recommended-btn .recommendation {
        top: -8px;
        right: 8px;
        font-size: 0.6em;
    }
    
    .instructions li {
        font-size: 1rem;
    }
    
    .dark-mode-toggle {
        position: fixed;
        top: 10px;
        right: 10px;
    }
}