/* Basic CSS Reset */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Noto Sans TC', 'Microsoft JhengHei', sans-serif; /* 優先使用思源黑體，其次微軟正黑體 */
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--background-color);
    padding-top: 80px; /* Space for fixed header */
}

/* Color Variables */
:root {
    --primary-color: #2C3E50; /* Dark Blue/Charcoal - Professional, Modern */
    --secondary-color: #7F8C8D; /* Soft Gray - For secondary text/elements */
    --accent-color: #1ABC9C; /* Teal/Turquoise - Energetic, Tech-savvy accent */
    --text-color: #34495E; /* Darker Blue-Gray - Main text color */
    --light-text-color: #ECF0F1; /* Off-White - For text on dark backgrounds */
    --background-color: #ffffff; /* Pure White */
    --light-background-color: #F8F9F9; /* Very Light Gray - For section backgrounds */
    --border-color: #BDC3C7; /* Light Gray - For borders */
    --shadow-color: rgba(44, 62, 80, 0.15); /* Subtle shadow based on primary color */
}

/* Header/Navigation Bar */
header {
    background-color: var(--background-color);
    box-shadow: 0 2px 10px var(--shadow-color);
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    padding: 15px 0;
}

header .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo a {
    font-size: 1.8em;
    font-weight: bold;
    color: var(--primary-color);
    text-decoration: none;
}

.nav-links {
    display: flex;
    list-style: none;
}

.nav-links li {
    margin-left: 30px;
}

.nav-links a {
    color: var(--text-color);
    text-decoration: none;
    font-size: 1.1em;
    font-weight: 500;
    transition: color 0.3s ease;
}

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

.burger {
    display: none;
    cursor: pointer;
}

.burger div {
    width: 25px;
    height: 3px;
    background-color: var(--text-color);
    margin: 5px;
    transition: all 0.3s ease;
}

/* Responsive Navigation */
@media (max-width: 768px) {
    body {
        padding-top: 70px; /* Adjust for smaller header on mobile */
    }

    header {
        padding: 10px 0;
    }

    .nav-links {
        position: absolute;
        right: 0;
        top: 60px; /* Below header */
        height: calc(100vh - 60px); /* Full height minus header */
        background-color: var(--background-color);
        display: flex;
        flex-direction: column;
        align-items: center;
        width: 70%;
        transform: translateX(100%);
        transition: transform 0.5s ease-in;
        z-index: 999;
        box-shadow: -2px 0 10px var(--shadow-color);
    }

    .nav-links li {
        opacity: 0;
        margin: 20px 0;
    }

    .nav-links.nav-active {
        transform: translateX(0%);
    }

    .burger {
        display: block;
    }

    /* Burger Animation */
    .toggle .line1 {
        transform: rotate(-45deg) translate(-5px, 6px);
    }

    .toggle .line2 {
        opacity: 0;
    }

    .toggle .line3 {
        transform: rotate(45deg) translate(-5px, -6px);
    }
}

/* General Styles */
:root {
    --primary-color: #007bff; /* Blue */
    --secondary-color: #6c757d; /* Gray */
    --accent-color: #28a745; /* Green for success/accent */
    --text-color: #333;
    --light-text-color: #f8f9fa;
    --background-color: #ffffff;
    --light-background-color: #f4f7f6;
    --border-color: #dee2e6;
    --shadow-color: rgba(0, 0, 0, 0.1);
}

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

section {
    padding: 80px 0;
    text-align: center;
}

h2 {
    font-size: 2.5em;
    margin-bottom: 40px;
    color: var(--primary-color);
}

h3 {
    font-size: 1.8em;
    margin-bottom: 15px;
    color: var(--text-color);
}

p {
    font-size: 1.1em;
    margin-bottom: 20px;
}

.btn {
    display: inline-block;
    background-color: var(--primary-color);
    color: var(--light-text-color);
    padding: 15px 30px;
    border-radius: 5px;
    text-decoration: none;
    font-size: 1.1em;
    transition: background-color 0.3s ease;
}

.btn:hover {
    background-color: #0056b3;
}

/* Hero Section */
#hero {
    background: url('images/placeholder_hero.jpg') no-repeat center center/cover;
    color: var(--light-text-color);
    padding: 150px 0;
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 600px; /* Ensure enough height */
    position: relative;
}

#hero::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5); /* Overlay for better text readability */
    z-index: 1;
}

.hero-content {
    position: relative;
    z-index: 2;
    max-width: 800px;
    margin: 0 auto;
    padding: 20px;
}

#hero h1 {
    font-size: 3.5em;
    margin-bottom: 20px;
    color: var(--light-text-color);
}

#hero h2 {
    font-size: 2em;
    margin-bottom: 30px;
    color: var(--light-text-color);
}

#hero p {
    font-size: 1.3em;
    margin-bottom: 40px;
    color: var(--light-text-color);
}

/* About Section */
#about {
    background-color: var(--light-background-color);
}

#about p {
    max-width: 800px;
    margin: 0 auto 20px auto;
}

/* Features Section */
#features {
    background-color: var(--background-color);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-top: 40px;
}

.feature-item {
    background-color: var(--light-background-color);
    padding: 30px;
    border-radius: 10px;
    box-shadow: var(--shadow-color) 0px 4px 12px;
    transition: transform 0.3s ease;
}

.feature-item:hover {
    transform: translateY(-10px);
}

.feature-item .feature-icon {
    width: 80px;
    height: 80px;
    background-color: var(--accent-color); /* Placeholder color */
    border-radius: 50%;
    margin: 0 auto 20px auto;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2em;
    color: var(--light-text-color);
}

.feature-item h3 {
    color: var(--primary-color);
}

/* Value Proposition Section */
#value-proposition {
    background-color: var(--primary-color);
    color: var(--light-text-color);
}

#value-proposition h2 {
    color: var(--light-text-color);
}

#value-proposition h3 {
    color: var(--light-text-color);
}

.value-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 30px;
    margin-top: 40px;
}

.value-item {
    background-color: rgba(255, 255, 255, 0.1);
    padding: 30px;
    border-radius: 10px;
    box-shadow: var(--shadow-color) 0px 4px 12px;
}

/* Testimonials Section */
#testimonials {
    background-color: var(--light-background-color);
}

.testimonial-quote {
    font-style: italic;
    font-size: 1.2em;
    max-width: 800px;
    margin: 0 auto 50px auto;
    color: var(--secondary-color);
}

.partner-logos {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 40px;
    margin-top: 40px;
}

.partner-logos img {
    max-width: 150px;
    height: auto;
    filter: grayscale(100%); /* Make logos grayscale */
    opacity: 0.7;
    transition: filter 0.3s ease, opacity 0.3s ease;
}

.partner-logos img:hover {
    filter: grayscale(0%);
    opacity: 1;
}

/* Contact Section */
#contact {
    background: url('images/placeholder_contact_us.jpg') no-repeat center center/cover;
    color: var(--light-text-color);
    padding: 80px 0;
    position: relative;
}

#contact::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.6); /* Darker overlay */
    z-index: 1;
}

#contact h2 {
    color: var(--light-text-color);
    position: relative;
    z-index: 2;
}

.contact-content {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 50px;
    margin-top: 40px;
    position: relative;
    z-index: 2;
}

.contact-form-container {
    background-color: rgba(255, 255, 255, 0.95); /* Slightly transparent white */
    padding: 40px;
    border-radius: 10px;
    box-shadow: var(--shadow-color) 0px 8px 24px;
    max-width: 500px;
    width: 100%;
}

#contact-form input, #contact-form textarea {
    width: 100%; /* Full width */
    padding: 15px;
    margin-bottom: 20px;
    border: 1px solid var(--border-color);
    border-radius: 8px; /* More rounded corners */
    font-size: 1.1em;
    color: var(--text-color);
    background-color: var(--light-background-color); /* Light background for inputs */
    transition: border-color 0.3s ease, box-shadow 0.3s ease;
}

#contact-form input:focus, #contact-form textarea:focus {
    border-color: var(--primary-color); /* Highlight on focus */
    box-shadow: 0 0 0 3px rgba(44, 62, 80, 0.2); /* Soft focus glow */
    outline: none;
}

#contact-form input::placeholder, #contact-form textarea::placeholder {
    color: var(--secondary-color);
}

#contact-form button {
    width: 100%;
    border: none;
    cursor: pointer;
    background-color: var(--accent-color); /* Use accent color for button */
    color: var(--light-text-color);
    padding: 15px 30px;
    border-radius: 8px; /* Match input border-radius */
    font-size: 1.1em;
    transition: background-color 0.3s ease, transform 0.2s ease;
}

#contact-form button:hover {
    background-color: #16A085; /* Slightly darker accent on hover */
    transform: translateY(-2px);
}

.form-message {
    margin-top: 20px;
    padding: 15px;
    border-radius: 8px;
    font-size: 1.1em;
    text-align: center;
    display: none; /* Hidden by default */
}

.form-message.success {
    background-color: #D4EDDA; /* Light green */
    color: #155724; /* Dark green text */
    border: 1px solid #C3E6CB;
}

.form-message.error {
    background-color: #F8D7DA; /* Light red */
    color: #721C24; /* Dark red text */
    border: 1px solid #F5C6CB;
}

.contact-info {
    background-color: rgba(0, 0, 0, 0.5); /* Dark transparent background */
    color: var(--light-text-color);
    padding: 40px;
    border-radius: 10px;
    max-width: 400px;
    width: 100%;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
}

.contact-info h3 {
    color: var(--light-text-color);
    margin-bottom: 20px;
}

.contact-info p {
    margin-bottom: 10px;
    font-size: 1.1em;
}

.contact-info img {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    margin-top: 30px;
    box-shadow: var(--shadow-color) 0px 4px 12px;
}

/* Footer */
footer {
    background-color: var(--text-color);
    color: var(--light-text-color);
    padding: 30px 0;
    font-size: 0.9em;
}

/* Responsive Design */
@media (max-width: 768px) {
    h1 {
        font-size: 2.5em;
    }

    h2 {
        font-size: 2em;
    }

    p {
        font-size: 1em;
    }

    .btn {
        padding: 12px 25px;
        font-size: 1em;
    }

    #hero {
        padding: 100px 0;
        min-height: 500px;
    }

    .features-grid, .value-grid, .contact-content {
        grid-template-columns: 1fr;
    }

    .feature-item, .value-item, .contact-form-container, .contact-info {
        max-width: 100%;
    }

    .partner-logos {
        gap: 20px;
    }

    .partner-logos img {
        max-width: 100px;
    }

    section {
        padding: 60px 0;
    }
}

@media (max-width: 480px) {
    #hero h1 {
        font-size: 2em;
    }

    #hero h2 {
        font-size: 1.5em;
    }

    #hero p {
        font-size: 1em;
    }

    .hero-content {
        padding: 15px;
    }

    .feature-item img {
        width: 80px;
        height: 80px;
    }

    .contact-form-container, .contact-info {
        padding: 20px;
    }
}