/* 1. RESET */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

/* 2. PAGE SETTINGS */
html {
    scroll-behavior: smooth;
    scroll-snap-type: y mandatory;
}

body {
    font-family: Arial, sans-serif;
    background: #111;
}

/* 3. PORTFOLIO CONTAINER */
.portfolio {
    width: 85%;
    margin: 0 auto;
}

/* 4. GENERAL PAGE SETTINGS */
.page {
    width: 100%;
    height: 100vh;
    height: 100svh;
    position: relative;
    scroll-snap-align: start;
    scroll-snap-stop: always;
    overflow: hidden;
}

/* 5. COVER & INTRODUCTION */
.cover img,
.introduction img {
    width: 85%;
    height: 85%;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    object-fit: contain;
}

/* 6. OPTIONS BACKGROUND */
.options-bg {
    width: 85%;
    height: 85%;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    object-fit: contain;
    z-index: 1;
}

/* 7. SWIPE INSTRUCTION */
.swipe-hint {
    position: absolute;
    bottom: 35px;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    color: white;
    font-size: 11px;
    letter-spacing: 2px;
    z-index: 2;
}

/* 8. OPTION BUTTONS */
.option-btn {
    position: absolute;
    z-index: 2;
    width: 225px;
    left: 50%;
    transform: translateX(-48.5%);
}

.option-btn img {
    width: 100%;
    height: auto;
    display: block;
}

/* BUTTON POSITIONS */
.btn-architecture {
    top: 38.5%;
}

.btn-design {
    top: 48%;
}

.btn-research {
    top: 59%;
}

/* 9. ARCHITECTURE SLIDES */
.architecture-slide img {
    width: 85%;
    height: 85%;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    object-fit: contain;
}

/* 10. DESIGN SLIDES */
.design-slide img {
    width: 85%;
    height: 85%;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    object-fit: contain;
}

/* 11. RESEARCH SLIDES */
.research-slide img {
    width: 85%;
    height: 85%;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    object-fit: contain;
}

/* 11. DESIGN & RESEARCH PLACEHOLDERS */
.design,
.research {
    color: white;
    display: flex;
    justify-content: center;
    align-items: center;
}

/* 12. BACK TO MENU BUTTON */
.back-to-menu {
    position: fixed;
    top: 25px;
    left: 25px;
    z-index: 100;

    color: white;
    text-decoration: none;
    font-size: 11px;
    letter-spacing: 1.5px;

    padding: 10px 14px;
    border: 1px solid rgba(255, 255, 255, 0.5);

    display: none;
    transition: 0.3s ease;
}

.back-to-menu:hover {
    background: white;
    color: #111;
}