:root {
    --primary: #ff6600;
    /* YC Orange */
    --primary-hover: #e55c00;
    --black: #000000;
    --text-main: #1a1a1a;
    --text-secondary: #4f4f4f;
    --bg-light: #f9f9f9;
    --white: #ffffff;
    --border: #eeeeee;
    --container-width: 1100px;
    --transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    color: var(--text-main);
    line-height: 1.6;
    background-color: var(--white);
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 24px;
}

h1,
h2,
h3,
h4 {
    color: var(--black);
    line-height: 1.2;
    font-weight: 700;
}

/* Navbar */
.navbar {
    height: 80px;
    display: flex;
    align-items: center;
    background: var(--white);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
}

.logo {
    display: flex;
    align-items: center;
    gap: 12px;
    text-decoration: none;
}

.yc-box {
    background-color: var(--primary);
    color: var(--white);
    font-weight: 800;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
}

.logo-text {
    font-weight: 700;
    font-size: 20px;
    color: var(--black);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 32px;
}

.nav-links a {
    text-decoration: none;
    color: var(--text-secondary);
    font-weight: 500;
    font-size: 15px;
    transition: var(--transition);
}

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

.btn-apply-nav {
    background-color: var(--primary);
    color: var(--white) !important;
    padding: 10px 20px;
    border-radius: 4px;
}

.btn-apply-nav:hover {
    background-color: var(--primary-hover);
}

.mobile-menu-btn {
    display: none;
    cursor: pointer;
    font-size: 24px;
}

/* Hero Section */
.hero {
    padding: 120px 0 80px;
    background-color: var(--white);
}

.hero-content {
    max-width: 800px;
}

.hero h1 {
    font-size: 72px;
    letter-spacing: -2px;
    margin-bottom: 24px;
}

.hero-subtitle {
    font-size: 24px;
    color: var(--primary);
    font-weight: 600;
    margin-bottom: 32px;
}

.hero-description {
    font-size: 20px;
    color: var(--text-secondary);
    margin-bottom: 48px;
    line-height: 1.5;
}

.btn-primary {
    display: inline-block;
    background-color: var(--primary);
    color: var(--white);
    padding: 18px 36px;
    font-size: 18px;
    font-weight: 600;
    text-decoration: none;
    border-radius: 4px;
    transition: var(--transition);
}

.btn-primary:hover {
    background-color: var(--primary-hover);
    transform: translateY(-2px);
}

/* Vision Section */
.vision-section {
    padding: 100px 0;
    background-color: var(--bg-light);
    border-top: 1px solid var(--border);
    border-bottom: 1px solid var(--border);
}

.vision-box {
    margin-bottom: 40px;
}

.vision-text {
    font-size: 48px;
    letter-spacing: -1px;
    font-weight: 800;
    color: var(--black);
}

.vision-description {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 48px;
    font-size: 18px;
    color: var(--text-secondary);
}

/* About Grid */
.about-section {
    padding: 100px 0;
}

.grid-wrap {
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: 80px;
    align-items: center;
}

.about-text h3 {
    font-size: 36px;
    margin-bottom: 24px;
}

.about-text p {
    font-size: 18px;
    margin-bottom: 20px;
    color: var(--text-secondary);
}

.about-features {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.feature-card {
    background: var(--white);
    border: 1px solid var(--border);
    padding: 30px;
    border-radius: 8px;
    transition: var(--transition);
}

.feature-card:hover {
    border-color: var(--primary);
    transform: translateY(-5px);
}

.feature-card i {
    font-size: 24px;
    color: var(--primary);
    margin-bottom: 16px;
}

.feature-card h4 {
    font-size: 16px;
    margin-bottom: 8px;
}

/* Steps Section */
.steps-section {
    padding: 100px 0;
    background: var(--black);
    color: var(--white);
}

.steps-section h2 {
    color: var(--white);
    font-size: 36px;
    margin-bottom: 60px;
    text-align: center;
}

.steps-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 40px;
}

.step {
    position: relative;
}

.step-num {
    font-size: 14px;
    font-weight: 800;
    color: var(--primary);
    display: block;
    margin-bottom: 16px;
    letter-spacing: 2px;
}

.step h4 {
    color: var(--white);
    margin-bottom: 12px;
    font-size: 20px;
}

.step p {
    color: #ccc;
    font-size: 15px;
}

/* Grid Section */
.grid-section {
    padding: 100px 0;
    background: var(--white);
}

.grid-layout {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 100px;
}

.grid-col h3 {
    font-size: 32px;
    margin-bottom: 32px;
}

.check-list {
    list-style: none;
}

.check-list li {
    position: relative;
    padding-left: 32px;
    margin-bottom: 16px;
    font-size: 16px;
    color: var(--text-secondary);
}

.check-list li::before {
    content: "→";
    position: absolute;
    left: 0;
    color: var(--primary);
    font-weight: 700;
}

/* Impact Section */
.impact-section {
    padding: 80px 0;
    background-color: var(--bg-light);
}

.impact-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.impact-content h3 {
    font-size: 36px;
    margin-bottom: 24px;
}

.impact-content p {
    font-size: 20px;
    color: var(--text-secondary);
}

/* Entrepreneur Section */
.entrepreneur-section {
    padding: 100px 0;
}

.entrepreneur-bg {
    background: var(--bg-light);
    padding: 80px;
    border-radius: 12px;
}

.entrepreneur-bg h3 {
    font-size: 36px;
    margin-bottom: 48px;
    text-align: center;
}

.e-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 48px;
}

.e-item h4 {
    font-size: 20px;
    color: var(--primary);
    margin-bottom: 12px;
}

.e-item p {
    color: var(--text-secondary);
}

/* Apply Section */
.apply-section {
    padding: 120px 0;
    background: var(--white);
}

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

.form-header h2 {
    font-size: 48px;
    margin-bottom: 16px;
}

.form-header p {
    font-size: 18px;
    color: var(--text-secondary);
}

.form-container {
    max-width: 800px;
    margin: 0 auto;
    background: var(--white);
    padding: 40px;
    border: 1px solid var(--border);
    border-radius: 8px;
}

.form-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 24px;
}

.field {
    margin-bottom: 24px;
}

label {
    display: block;
    font-weight: 600;
    margin-bottom: 8px;
    font-size: 14px;
}

input,
textarea {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid var(--border);
    border-radius: 4px;
    font-family: inherit;
    font-size: 16px;
    transition: var(--transition);
}

input:focus,
textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(255, 102, 0, 0.1);
}

.form-actions {
    margin-top: 32px;
}

.btn-submit {
    width: 100%;
    padding: 18px;
    background: var(--primary);
    color: var(--white);
    border: none;
    border-radius: 4px;
    font-size: 18px;
    font-weight: 700;
    cursor: pointer;
    transition: var(--transition);
}

.btn-submit:hover {
    background: var(--primary-hover);
}

/* Call to Action */
.call-to-action {
    padding: 100px 0;
    background: var(--primary);
    color: var(--white);
}

.cta-inner {
    text-align: center;
    max-width: 800px;
    margin: 0 auto;
}

.cta-inner h2 {
    color: var(--white);
    font-size: 48px;
    margin-bottom: 24px;
}

.cta-inner p {
    font-size: 20px;
    margin-bottom: 40px;
    opacity: 0.9;
}

.cta-highlights {
    display: flex;
    justify-content: center;
    gap: 40px;
    font-weight: 800;
    font-size: 20px;
}

/* Footer */
.footer {
    padding: 60px 0;
    border-top: 1px solid var(--border);
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    color: var(--text-secondary);
    font-size: 14px;
}

.social-links {
    display: flex;
    gap: 24px;
}

.social-links a {
    color: var(--text-secondary);
    font-size: 20px;
    transition: var(--transition);
}

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

/* Responsive */
/* Reveal Animation */
.reveal {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

@media (max-width: 991px) {
    .hero h1 {
        font-size: 56px;
    }

    .grid-wrap,
    .grid-layout,
    .vision-description {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .steps-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .e-grid {
        grid-template-columns: 1fr;
        gap: 32px;
    }
}

@media (max-width: 767px) {
    .hero h1 {
        font-size: 40px;
    }

    .nav-links {
        display: none;
    }

    .mobile-menu-btn {
        display: block;
    }

    .form-grid {
        grid-template-columns: 1fr;
    }

    .steps-grid {
        grid-template-columns: 1fr;
    }

    .cta-highlights {
        flex-direction: column;
        gap: 12px;
    }

    .footer-bottom {
        flex-direction: column;
        gap: 24px;
        text-align: center;
    }
}

/* Toast Notification */
.toast-container {
    position: fixed;
    bottom: 30px;
    right: 30px;
    z-index: 10000;
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.toast {
    background: var(--black);
    color: var(--white);
    padding: 16px 24px;
    border-radius: 8px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    display: flex;
    align-items: center;
    gap: 12px;
    min-width: 300px;
    transform: translateX(120%);
    transition: transform 0.4s cubic-bezier(0.16, 1, 0.3, 1);
    border-left: 4px solid var(--primary);
}

.toast.show {
    transform: translateX(0);
}

.toast.error {
    border-left-color: #ff4444;
}

.toast-icon {
    font-size: 18px;
    color: var(--primary);
}

.toast.error .toast-icon {
    color: #ff4444;
}

.toast-message {
    font-size: 14px;
    font-weight: 500;
}

@media (max-width: 767px) {
    .toast-container {
        bottom: 20px;
        right: 20px;
        left: 20px;
    }

    .toast {
        min-width: auto;
    }
}